Question

我试图用javafxports编写一个简单的sqlite代码。

的build.gradle：

    buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'org.javafxports:jfxmobile-plugin:1.0.6'
    }
}

apply plugin: 'org.javafxports.jfxmobile'

repositories {
    jcenter()
    maven {
        url "https://oss.sonatype.org/content/repositories/snapshots/"
    }
    maven {
        url "https://oss.sonatype.org/content/repositories/releases"
    }

}

ext.CHARM_DOWN_VERSION = "1.0.0"

dependencies{
    compile 'org.xerial:sqlite-jdbc:3.8.11'

    compile "com.gluonhq:charm-down-common:$CHARM_DOWN_VERSION"
    desktopRuntime "com.gluonhq:charm-down-desktop:$CHARM_DOWN_VERSION"
    androidRuntime "com.gluonhq:charm-down-android:$CHARM_DOWN_VERSION"
    iosRuntime "com.gluonhq:charm-down-ios:$CHARM_DOWN_VERSION"
}
mainClassName = 'com.gluonapplication.version16'

jfxmobile {
    android {
        manifest = 'src/android/AndroidManifest.xml'
    }
    ios {
        infoPList = file('src/ios/Default-Info.plist')
        forceLinkClasses= ['com.gluonhq.**.*', 'org.sqlite.**.*']
    }
}

我的JavaCode：

public static Label msg = new Label();

@Override
public void start(Stage stage) {
    StackPane root = new StackPane();

    root.getChildren().add(msg);
    Rectangle2D visualBounds = Screen.getPrimary().getVisualBounds();
    Scene scene = new Scene(root, visualBounds.getWidth(), visualBounds.getHeight());

    stage.getIcons().add(new Image(version16.class.getResourceAsStream("/icon.png")));
    stage.setScene(scene);
    stage.show();

    try {
        testSqli();
    } catch (SQLException e) {
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
}
public static void testSqli() throws SQLException, ClassNotFoundException {
    String driver = "org.sqlite.JDBC";
    //Class.forName("SQLite.JDBCDriver");
    Class.forName(driver);
    String dbName = "mtt8.db";
    String dbUrl = "jdbc:sqlite:" + dbName;

    //create table
    Statement st = null;
    Connection conn = DriverManager.getConnection(dbUrl);
    st = conn.createStatement();
    st.executeUpdate("DROP TABLE IF EXISTS village;");
    st.executeUpdate("CREATE table village (id int, name varchar(20))");
    //insert row?
    st.executeUpdate("INSERT INTO village VALUES (111, 'Concretepage')");

    //select?
    String query = "SELECT id, name from village";
    ResultSet rs = null;
    rs = st.executeQuery(query);

    while (rs.next()) {
        int id = 0;
        id = rs.getInt(1);
        String name = null;
        name = rs.getString(2);
        msg.setText("id:" + id + ", name: " + name);
        System.out.println("id:" + id + ", name: " + name);
        st.executeUpdate("DELETE from village");
        rs.close();
    }
}

我发送 ./ gradlew launchIOSDevice 并收到以下错误：

java.sql.SQLException: opening db: 'mtt8.db': open failed: EPERM (Operation not permitted)
    at org.sqlite.core.CoreConnection.open(CoreConnection.java:203)
    at org.sqlite.core.CoreConnection.<init>(CoreConnection.java:76)
    at org.sqlite.jdbc3.JDBC3Connection.<init>(JDBC3Connection.java:24)
    at org.sqlite.jdbc4.JDBC4Connection.<init>(JDBC4Connection.java:23)
    at org.sqlite.SQLiteConnection.<init>(SQLiteConnection.java:45)
    at org.sqlite.JDBC.createConnection(JDBC.java:114)
    at org.sqlite.JDBC.connect(JDBC.java:88)
    at java.sql.DriverManager.getConnection(DriverManager.java:179)
    at java.sql.DriverManager.getConnection(DriverManager.java:144)
    at com.gluonapplication.version16.testSqli(version16.java:48)
    at com.gluonapplication.version16.start(version16.java:32)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863)
    at com.sun.javafx.application.LauncherImpl$$Lambda$81.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326)
    at com.sun.javafx.application.PlatformImpl$$Lambda$93.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
    at com.sun.javafx.application.PlatformImpl$$Lambda$105.run(Unknown Source)
    at java.security.AccessController.doPrivileged(AccessController.java:52)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
    at com.sun.javafx.application.PlatformImpl$$Lambda$92.run(Unknown Source)
    at org.robovm.apple.uikit.UIApplication.main(Native Method)
    at org.robovm.apple.uikit.UIApplication.main(UIApplication.java:369)
    at org.javafxports.jfxmobile.ios.BasicLauncher.main(BasicLauncher.java:115)
IOSWindowSystemInterface : setSwapInterval unimp
setSwapInterval(1)

是的，有人可以帮帮我吗我如何在我的代码中提供访问权限以便我可以创建一个sqlite DB？

感谢 erkan kaplan

Answer 1

正如@ItachiUchiha所指出的，您的问题与您尝试创建数据库的地方有关：

String dbUrl = "jdbc:sqlite:" + dbName;
Connection conn = DriverManager.getConnection(dbUrl);

您提供的网址可能适用于您的桌面，但不适用于移动设备，其中应用对存储的访问权限非常有限，并且只允许访问私有本地存储。

使用Gluon的开源库Charm-Down，无论应用程序运行的平台如何，都可以轻松获取本地存储的路径。

首先，将这些依赖项添加到build.gradle脚本中：

ext.CHARM_DOWN_VERSION = "1.0.0"
dependencies {
    compile "com.gluonhq:charm-down-common:$CHARM_DOWN_VERSION"
    desktopRuntime "com.gluonhq:charm-down-desktop:$CHARM_DOWN_VERSION"
    androidRuntime "com.gluonhq:charm-down-android:$CHARM_DOWN_VERSION"
    iosRuntime "com.gluonhq:charm-down-ios:$CHARM_DOWN_VERSION"
}

现在，在您的代码中，网址应为：

try {
    File dir = PlatformFactory.getPlatform().getPrivateStorage();
    File db = new File (dir, dbName);
    String dbUrl = "jdbc:sqlite:" + db.getAbsolutePath();
    Connection conn = DriverManager.getConnection(dbUrl);
    ...
} catch (Exception e) { }

Answer 2

非常感谢JOSE，

这是我的build.gradle，所以我可以连接到我的Lan上的mysql-server，结果保存为Ipad-Devices上的sqlite.db;

buildscript {
    repositories {
        jcenter()
        mavenCentral()
        maven { url 'https://oss.sonatype.org/content/repositories/snapshots' }
    }
    dependencies { classpath 'org.javafxports:jfxmobile-plugin:1.0.6' }
}

apply plugin: 'org.javafxports.jfxmobile'


repositories {
    jcenter()
    mavenCentral()
    maven { url 'https://oss.sonatype.org/content/repositories/snapshots' }
    maven { url 'https://oss.sonatype.org/content/repositories/releases' }
}

ext.CHARM_DOWN_VERSION = "1.0.0"

dependencies {
    compile 'mysql:mysql-connector-java:3.1.12'
    compile 'org.xerial:sqlite-jdbc:3.9.0-SNAPSHOT'

    compile "com.gluonhq:charm-down-common:$CHARM_DOWN_VERSION"
    desktopRuntime "com.gluonhq:charm-down-desktop:$CHARM_DOWN_VERSION"
    androidRuntime "com.gluonhq:charm-down-android:$CHARM_DOWN_VERSION"
    iosRuntime "com.gluonhq:charm-down-ios:$CHARM_DOWN_VERSION"
}




mainClassName = 'com.mtt8.version15'

jfxmobile {
    android {
        manifest = 'src/android/AndroidManifest.xml'
        packagingOptions {
            exclude 'META-INF/INDEX.LIST'
        }
    }

    ios {
        infoPList = file('src/ios/Default-Info.plist')
        forceLinkClasses = ['com.mtt8.**.*', 'com.mysql.**.*', 'SQLite.**.*', 'com.gluonhq.**.*']
    }

}

和sqlite.java

import com.gluonhq.charm.down.common.PlatformFactory;

import java.io.File;
import java.io.IOException;
import java.sql.*;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;



/**
 * Created by erkankaplan on 10.11.15.
 */
public class sqliteDBConnector {

    public static void testSqli() throws SQLException, ClassNotFoundException{
        Class.forName("SQLite.JDBCDriver");

        String dbName = "mtt8.db";
        File dir = null;
        try {
            dir = PlatformFactory.getPlatform().getPrivateStorage();
        } catch (IOException e) {
            e.printStackTrace();
        }

        File db = new File (dir, dbName);
        String dbUrl = "jdbc:sqlite:" + db.getAbsolutePath();




        Connection conn = DriverManager.getConnection(dbUrl);

        //create table
        Statement st=null;

            st = conn.createStatement();
            st.executeUpdate("DROP TABLE IF EXISTS village;");
        st.executeUpdate("CREATE table village (id int, name varchar(20))");
            //insert row
            st.executeUpdate("INSERT INTO village VALUES (111, 'Concretepage')");

        //select
        String query = "SELECT id, name from village";
        ResultSet rs = null;

                rs = st.executeQuery(query);

                while(rs.next()) {
                    int id = 0;
                    id = rs.getInt(1);

                    String name = null;

                        name = rs.getString(2);

                    System.out.println("id:"+ id+ ", name: "+ name);
                st.executeUpdate("DELETE from village");
                rs.close();

        }

    }

}

Javafxports和SQLite - ＆gt;开放失败：EPERM（不允许操作）

2 个答案: