Add chapters 9-17 for the java book

Java-Kompendium/kap17/build.gradle

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+plugins {
+  id 'application'
+  id 'org.openjfx.javafxplugin' version '0.1.0'
+}
+
+repositories {
+    mavenCentral()
+}
+
+javafx {
+    version = '21'
+    modules = ['javafx.controls']
+}
+
+dependencies {
+    runtimeOnly 'org.hsqldb:hsqldb:2.7.4'
+}
+
+run {
+    standardInput = System.in
+}
+
+application {
+    mainClass = 'Hauptfenster'
+}

Java-Kompendium/kap17/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

Java-Kompendium/kap17/gradlew

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+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

Java-Kompendium/kap17/gradlew.bat

@@ -0,0 +1,93 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

Java-Kompendium/kap17/src/main/java/ButtonAnzeigen.java

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+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.Insets;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.control.ScrollPane;
+import javafx.scene.layout.BorderPane;
+import javafx.scene.layout.VBox;
+import javafx.scene.text.Font;
+import javafx.scene.text.FontWeight;
+import javafx.scene.text.Text;
+import javafx.stage.Stage;
+import javafx.stage.Modality;
+import java.sql.*;
+
+public class ButtonAnzeigen extends Button {
+    public ButtonAnzeigen(String text) {
+        super(text);
+    }
+
+    public void neuesFenster(Stage hauptfenster) {
+        String host = "jdbc:hsqldb:mem:mitarbeiter";
+        String inhalt = "";
+
+        try {
+            Connection verbindung = DriverManager.getConnection(host);
+            Statement befehl = verbindung.createStatement();
+
+            String SQL = "SELECT * FROM Mitarbeiter";
+            ResultSet rs = befehl.executeQuery(SQL);
+            int zaehler = 0;
+            while (rs.next()) {
+                zaehler++;
+                inhalt += "Personalnummer: " + rs.getString("persnr") + "\n";
+                inhalt += "Nachname: " + rs.getString("name") + "\n";
+                inhalt += "Vorname: " + rs.getString("vorname") + "\n";
+                inhalt += "Gehalt: " + rs.getString("gehalt") + "\n\n";
+            }
+            if (zaehler == 0) {
+                inhalt = "Keine Mitarbeiter vorhanden.";
+            }
+        } catch (SQLException err) {
+            inhalt = err.getMessage();
+        }
+        VBox vbox = new VBox();
+        Text titel = new Text("Ihr Personal:\n");
+        titel.setFont(Font.font("Arial", FontWeight.NORMAL, 14));
+        vbox.getChildren().add(titel);
+        Text ausgabe = new Text(inhalt);
+        vbox.getChildren().add(ausgabe);
+
+        ScrollPane scrollPane = new ScrollPane(vbox);
+        scrollPane.setFitToWidth(true);
+        scrollPane.setPadding(new Insets(10));
+
+        BorderPane root = new BorderPane(scrollPane);
+        root.setPadding(new Insets(30));
+
+        Button btn = new Button("OK");
+        btn.setPadding(new Insets(5));
+        VBox vbox2 = new VBox();
+        vbox2.getChildren().add(btn);
+        vbox2.setPadding(new Insets(0, 0, 0, 0));
+        root.setBottom(vbox2);
+
+        Stage neuesFenster = new Stage();
+        neuesFenster.setTitle("Personal anzeigen");
+        neuesFenster.initModality(Modality.WINDOW_MODAL);
+        neuesFenster.initOwner(hauptfenster);
+        neuesFenster.setX(hauptfenster.getX() + 50);
+        neuesFenster.setY(hauptfenster.getY() + 50);
+        Scene scene = new Scene(root, 400, 300);
+        neuesFenster.setScene(scene);
+        neuesFenster.show();
+
+        btn.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                neuesFenster.close();
+            }
+        });
+    }
+}

Java-Kompendium/kap17/src/main/java/ButtonEntfernen.java

@@ -0,0 +1,89 @@
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.layout.GridPane;
+import javafx.stage.Stage;
+import javafx.stage.Modality;
+import javafx.scene.control.Label;
+import javafx.scene.control.TextField;
+import javafx.scene.text.Text;
+import javafx.scene.text.Font;
+import javafx.scene.text.FontWeight;
+import java.sql.*;
+
+public class ButtonEntfernen extends Button {
+    public ButtonEntfernen(String text) {
+        super(text);
+    }
+
+    public void neuesFenster(Stage hauptfenster) {
+        GridPane grid = new GridPane();
+        grid.setAlignment(Pos.CENTER);
+        grid.setHgap(10);
+        grid.setVgap(10);
+        grid.setPadding(new Insets(10, 10, 10, 10));
+        Scene scene = new Scene(grid, 400, 300);
+        Stage neuesFenster = new Stage();
+        neuesFenster.setTitle("Mitarbeiter entfernen");
+        neuesFenster.setScene(scene);
+        neuesFenster.initModality(Modality.WINDOW_MODAL);
+        neuesFenster.initOwner(hauptfenster);
+        neuesFenster.setX(hauptfenster.getX() + 50);
+        neuesFenster.setY(hauptfenster.getY() + 50);
+
+        Text titel = new Text("Geben Sie die Personalnummer des Mitarbeiters ein:");
+        titel.setFont(Font.font("Arial", FontWeight.NORMAL, 14));
+        grid.add(titel, 0, 0, 2, 1);
+
+        Label persnr = new Label("Personalnummer:");
+        grid.add(persnr, 0, 1);
+        TextField eingabePersnr = new TextField();
+        grid.add(eingabePersnr, 1, 1);
+
+        Button btnEntf = new Button("Mitarbeiter entfernen");
+        grid.add(btnEntf, 0, 5);
+        neuesFenster.show();
+
+        btnEntf.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                int persnr = -1;
+                boolean richtigeEingabe = false;
+                try {
+                    persnr = Integer.parseInt(eingabePersnr.getText());
+                    richtigeEingabe = true;
+                } catch (NumberFormatException Ausnahme) {
+                    Hinweis.ausgeben(hauptfenster, "Fehlerhafte Eingabe");
+                }
+                if (richtigeEingabe) {
+                    String host = "jdbc:hsqldb:mem:mitarbeiter";
+
+                    try {
+                        Connection verbindung = DriverManager.getConnection(host);
+                        Statement befehl = verbindung.createStatement();
+
+                        String SQL = "SELECT name FROM Mitarbeiter WHERE persnr = " + persnr;
+                        ResultSet rs = befehl.executeQuery(SQL);
+                        int zaehler = 0;
+                        while (rs.next()) {
+                            zaehler++;
+                        }
+                        if (zaehler > 0) {
+                            SQL = "DELETE FROM Mitarbeiter WHERE persnr = " + persnr;
+                            befehl.executeUpdate(SQL);
+                            Hinweis.ausgeben(hauptfenster, "Mitarbeiter erfolgreich entfernt.");
+                            neuesFenster.close();
+                        } else {
+                            Hinweis.ausgeben(hauptfenster, "Personalnummer nicht vorhanden");
+                        }
+                    } catch (SQLException err) {
+                        System.out.println(err.getMessage());
+                    }
+                }
+            }
+        });
+    }
+}

Java-Kompendium/kap17/src/main/java/ButtonGehalt.java

@@ -0,0 +1,107 @@
+import java.sql.Statement;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.control.Label;
+import javafx.scene.control.TextField;
+import javafx.scene.layout.GridPane;
+import javafx.scene.text.Font;
+import javafx.scene.text.FontWeight;
+import javafx.scene.text.Text;
+import javafx.stage.Modality;
+import javafx.stage.Stage;
+
+public class ButtonGehalt extends Button {
+    public ButtonGehalt(String text) {
+        super(text);
+    }
+
+    public void neuesFenster(Stage hauptfenster) {
+        GridPane grid = new GridPane();
+        grid.setAlignment(Pos.CENTER);
+        grid.setHgap(10);
+        grid.setVgap(10);
+        grid.setPadding(new Insets(10, 10, 10, 10));
+        Scene scene = new Scene(grid, 400, 300);
+        Stage neuesFenster = new Stage();
+        neuesFenster.setTitle("Mitarbeiter hinzufügen");
+        neuesFenster.setScene(scene);
+        neuesFenster.initModality(Modality.WINDOW_MODAL);
+        neuesFenster.initOwner(hauptfenster);
+        neuesFenster.setX(hauptfenster.getX() + 50);
+        neuesFenster.setY(hauptfenster.getY() + 50);
+
+        Text titel = new Text("Geben Sie die Daten für die Gehaltsanpassung ein:");
+        titel.setFont(Font.font("Arial", FontWeight.NORMAL, 14));
+        grid.add(titel, 0, 0, 2, 1);
+
+        Label persnr = new Label("Personalnummer:");
+        grid.add(persnr, 0, 1);
+        TextField eingabePersnr = new TextField();
+        grid.add(eingabePersnr, 1, 1);
+
+        Label gehalt = new Label("Gehalt:");
+        grid.add(gehalt, 0, 4);
+        TextField eingabeGehalt = new TextField();
+        grid.add(eingabeGehalt, 1, 4);
+
+        Button btnEinf = new Button("Gehalt anpassen");
+        grid.add(btnEinf, 0, 5);
+        neuesFenster.show();
+
+        btnEinf.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                int persnr = -1;
+                double gehalt = -1;
+                boolean richtigeEingabe = false;
+
+                try {
+                    persnr = Integer.parseInt(eingabePersnr.getText());
+                    gehalt = Double.parseDouble(eingabeGehalt.getText());
+                    richtigeEingabe = true;
+                }
+                catch (NumberFormatException Ausnahme) {
+                    Hinweis.ausgeben(hauptfenster, "Fehlerhafte Eingabe.");
+                }
+                if (richtigeEingabe) {
+                    String host = "jdbc:hsqldb:mem:mitarbeiter";
+
+                    try {
+                        Connection verbindung = DriverManager.getConnection(host);
+                        var befehl = verbindung.prepareStatement(
+                                "SELECT name FROM Mitarbeiter WHERE persnr = ?");
+
+                        befehl.setInt(1, persnr);
+                        ResultSet rs = befehl.executeQuery();
+                        int zaehler = 0;
+                        while (rs.next()) {
+                            zaehler++;
+                        }
+                        if (zaehler > 0) {
+                            befehl = verbindung.prepareStatement(
+                                "UPDATE Mitarbeiter SET gehalt = ? WHERE persnr = ?");
+                            befehl.setDouble(1, gehalt);
+                            befehl.setInt(2, persnr);
+                            befehl.executeUpdate();
+                            Hinweis.ausgeben(hauptfenster, "Gehalt erfolgreich angepasst.");
+                            neuesFenster.close();
+                        } else {
+                            Hinweis.ausgeben(hauptfenster, "Personalnummer nicht vorhanden");
+                        }
+                    } catch (SQLException err) {
+                        System.out.println(err.getMessage());
+                    }
+                }
+            }
+        });
+    }
+}

Java-Kompendium/kap17/src/main/java/ButtonHinzufuegen.java

@@ -0,0 +1,119 @@
+import java.sql.Statement;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.control.Label;
+import javafx.scene.control.TextField;
+import javafx.scene.layout.GridPane;
+import javafx.scene.text.Font;
+import javafx.scene.text.FontWeight;
+import javafx.scene.text.Text;
+import javafx.stage.Modality;
+import javafx.stage.Stage;
+
+public class ButtonHinzufuegen extends Button {
+    public ButtonHinzufuegen(String text) {
+        super(text);
+    }
+
+    public void neuesFenster(Stage hauptfenster) {
+        GridPane grid = new GridPane();
+        grid.setAlignment(Pos.CENTER);
+        grid.setHgap(10);
+        grid.setVgap(10);
+        grid.setPadding(new Insets(10, 10, 10, 10));
+        Scene scene = new Scene(grid, 400, 300);
+        Stage neuesFenster = new Stage();
+        neuesFenster.setTitle("Mitarbeiter hinzufügen");
+        neuesFenster.setScene(scene);
+        neuesFenster.initModality(Modality.WINDOW_MODAL);
+        neuesFenster.initOwner(hauptfenster);
+        neuesFenster.setX(hauptfenster.getX() + 50);
+        neuesFenster.setY(hauptfenster.getY() + 50);
+
+        Text titel = new Text("Geben Sie die Daten des neuen Mitarbeiters ein:");
+        titel.setFont(Font.font("Arial", FontWeight.NORMAL, 14));
+        grid.add(titel, 0, 0, 2, 1);
+
+        Label persnr = new Label("Personalnummer:");
+        grid.add(persnr, 0, 1);
+        TextField eingabePersnr = new TextField();
+        grid.add(eingabePersnr, 1, 1);
+
+        Label nachname = new Label("Nachname:");
+        grid.add(nachname, 0, 2);
+        TextField eingabeNachname = new TextField();
+        grid.add(eingabeNachname, 1, 2);
+
+        Label vorname = new Label("Vorname:");
+        grid.add(vorname, 0, 3);
+        TextField eingabeVorname = new TextField();
+        grid.add(eingabeVorname, 1, 3);
+
+        Label gehalt = new Label("Gehalt:");
+        grid.add(gehalt, 0, 4);
+        TextField eingabeGehalt = new TextField();
+        grid.add(eingabeGehalt, 1, 4);
+
+        Button btnEinf = new Button("Mitarbeiter hinzufügen");
+        grid.add(btnEinf, 0, 5);
+        neuesFenster.show();
+
+        btnEinf.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                String vorname = "";
+                String nachname = "";
+                int persnr = -1;
+                double gehalt = -1;
+                boolean richtigeEingabe = false;
+
+                try {
+                    vorname = eingabeVorname.getText();
+                    nachname = eingabeNachname.getText();
+                    persnr = Integer.parseInt(eingabePersnr.getText());
+                    gehalt = Double.parseDouble(eingabeGehalt.getText());
+                    richtigeEingabe = true;
+                }
+                catch (NumberFormatException Ausnahme) {
+                    Hinweis.ausgeben(hauptfenster, "Fehlerhafte Eingabe.");
+                }
+                if (richtigeEingabe) {
+                    String host = "jdbc:hsqldb:mem:mitarbeiter";
+
+                    try {
+                        Connection verbindung = DriverManager.getConnection(host);
+                        Statement befehl = verbindung.createStatement();
+
+                        String SQL = "SELECT name FROM Mitarbeiter WHERE persnr = " + persnr;
+                        ResultSet rs = befehl.executeQuery(SQL);
+                        int zaehler = 0;
+                        while (rs.next()) {
+                            zaehler++;
+                        }
+                        if (zaehler == 0) {
+                            SQL = "INSERT INTO Mitarbeiter (persnr, name, vorname,"
+                                + "gehalt) VALUES (" + persnr + ", '" +
+                                nachname + "', '" + vorname + "', " + gehalt + ")";
+                            befehl.executeUpdate(SQL);
+                            Hinweis.ausgeben(hauptfenster, "Mitarbeiter erfolgreich hinzufgefügt.");
+                            neuesFenster.close();
+                        } else {
+                            Hinweis.ausgeben(hauptfenster, "Personalnummer bereits vergeben");
+                        }
+                    } catch (SQLException err) {
+                        System.out.println(err.getMessage());
+                    }
+                }
+            }
+        });
+    }
+}

Java-Kompendium/kap17/src/main/java/Hauptfenster.java

@@ -0,0 +1,104 @@
+import java.sql.*;
+
+import javafx.application.Application;
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.HPos;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.layout.GridPane;
+import javafx.scene.text.Font;
+import javafx.scene.text.FontWeight;
+import javafx.scene.text.Text;
+import javafx.stage.Stage;
+
+public class Hauptfenster extends Application {
+    @Override
+    public void start(Stage stage) throws SQLException {
+        String host = "jdbc:hsqldb:mem:mitarbeiter";
+
+        Connection verbindung = DriverManager.getConnection(host);
+        Statement befehl = verbindung.createStatement();
+        String SQL = """
+            CREATE TABLE Mitarbeiter (
+                persnr INTEGER Primary Key Not Null,
+                name VARCHAR(30),
+                vorname VARCHAR(30),
+                gehalt DECIMAL(9,2)
+            )
+        """;
+        befehl.executeUpdate(SQL);
+
+        GridPane grid = new GridPane();
+        grid.setAlignment(Pos.CENTER);
+        grid.setHgap(30);
+        grid.setVgap(50);
+        grid.setPadding(new Insets(20, 20, 20, 20));
+        stage.setTitle("Personalverwaltung");
+        Text titel = new Text("Wählen Sie eine Aktion aus:");
+        titel.setFont(Font.font("Arial", FontWeight.BOLD, 14));
+        grid.add(titel, 0, 0, 2, 1);
+
+        ButtonHinzufuegen btn1 = new ButtonHinzufuegen("Mitarbeiter hinzufügen");
+        grid.add(btn1, 0, 1);
+        btn1.setPrefSize(200, 50);
+
+        ButtonEntfernen btn2 = new ButtonEntfernen("Mitarbeiter entfernen");
+        grid.add(btn2, 1, 1);
+        btn2.setPrefSize(200, 50);
+
+        ButtonGehalt btn3 = new ButtonGehalt("Gehalt anpassen");
+        grid.add(btn3, 0, 2);
+        btn3.setPrefSize(200, 50);
+
+        ButtonAnzeigen btn4 = new ButtonAnzeigen("Personal anzeigen");
+        grid.add(btn4, 1, 2);
+        btn4.setPrefSize(200, 50);
+
+        Button btn5 = new Button("OK");
+        grid.add(btn5, 0, 3, 2, 1);
+        btn5.setPrefSize(100, 20);
+        GridPane.setHalignment(btn5, HPos.CENTER);
+
+        btn1.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                btn1.neuesFenster(stage);
+            }
+        });
+        btn2.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                btn2.neuesFenster(stage);
+            }
+        });
+        btn3.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                btn3.neuesFenster(stage);
+            }
+        });
+        btn4.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                btn4.neuesFenster(stage);
+            }
+        });
+        btn5.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                stage.close();
+            }
+        });
+
+        Scene scene = new Scene(grid, 600, 400);
+        stage.setScene(scene);
+        stage.show();
+    }
+
+    public static void main(String[] args) {
+        launch(args);
+    }
+}

Java-Kompendium/kap17/src/main/java/Hinweis.java

@@ -0,0 +1,39 @@
+import javafx.event.ActionEvent;
+import javafx.event.EventHandler;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.control.Label;
+import javafx.scene.layout.GridPane;
+import javafx.stage.Modality;
+import javafx.stage.Stage;
+
+public class Hinweis {
+    public static void ausgeben(Stage fenster, String text) {
+        GridPane grid = new GridPane();
+        grid.setAlignment(Pos.CENTER);
+        grid.setHgap(10);
+        grid.setVgap(10);
+        grid.setPadding(new Insets(10, 10, 10, 10));
+
+        Scene scene = new Scene(grid, 300, 200);
+        Label label = new Label(text);
+        Button btn = new Button("OK");
+        grid.add(label, 0, 0);
+        grid.add(btn, 0, 1);
+        Stage hinweisfenster = new Stage();
+        hinweisfenster.initModality(Modality.WINDOW_MODAL);
+        hinweisfenster.initOwner(fenster);
+        hinweisfenster.setX(fenster.getX() + 30);
+        hinweisfenster.setY(fenster.getY() + 30);
+        hinweisfenster.setScene(scene);
+        hinweisfenster.show();
+        btn.setOnAction(new EventHandler<ActionEvent>() {
+            @Override
+            public void handle(ActionEvent e) {
+                hinweisfenster.close();
+            }
+        });
+    }
+}