Question

当我尝试在Android上直接使用JDBC连接MySQL数据库时，我得到了这样的例外：

Caused by: java.lang.ClassNotFoundException: Didn't find class "java.sql.SQLType" on path: DexPathList[[zip file "/system/framework/org.apache.http.legacy.boot.jar",...

我的测试代码在这里：

package com.kurosei.app.test;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        try {
            Class.forName("com.mysql.cj.jdbc.Driver").newInstance();
            Connection conn = DriverManager.getConnection(URL,USER,PWD);
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

我的 build.gradle 就在这里：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    defaultConfig {
        applicationId "com.kurosei.app.test"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        targetCompatibility 1.8
        sourceCompatibility 1.8
    }

}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'mysql:mysql-connector-java:8.0.11'

}

JDK的版本是1.8.0_152
Gradle Plugin的版本是3.1.3
Android Studio版本为3.1.2

不要问为什么我选择这种方式来访问数据库......

Answer 1

您可以使用Play商店上名为RemoDB的现有应用程序来连接数据库。如果您仍然想连接自己，则可以尝试使用jdbc驱动程序的6.x.x版本

Answer 2

您可能希望包括在下面的gradle中添加的JBoss JDBC Wrapper

implementation files('libs/jboss-common-jdbc-wrapper.jar')

ClassNotFoundException：在路径上找不到类“java.sql.SQLType”：DexPathList

2 个答案: