运行错误java.lang.ClassNotFoundException
来源：4-2 JDBC的工具类的抽取二
XXXXg
2019-11-01 15:33:02
driverClass=com.mysql.jdbc.Driver;
url=jdbc:mysql://localhost:3306 + /jdbctest+?useSSL=false&serverTimezone=UCT&useUnicode=true&characterEncoding=utf-8;
username=root;
password=0218;
package com.imooc.jdbc.utils;
import java.sql.Connection;
import java.sql.Statement;
import org.junit.Test;
public class JDBCDemo3 {
@Test
//保存记录
public void demo1() {
Connection conn = null;
Statement stmt = null;
try {
//获得连接
conn = JDBCUtils.getConnection();
//创建执行SQL语句
stmt = conn.createStatement();
//编写SQL语句
String sql = "insert into user values (null,'fff','123','小六')";
//执行SQL语句
int i = stmt.executeUpdate(sql);
if(i>0) {
System.out.println("保存成功");
}
}catch(Exception e) {
e.printStackTrace();
}finally {
//释放资源
JDBCUtils.release(stmt, conn);
}
}
}
package com.imooc.jdbc.utils;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
/**
* JDBC工具类
* @author 不忘初心。
*
*/
public class JDBCUtils {
//把连接的帐户密码设置为静态常量
private static final String driverClass;
private static final String url;
private static final String username;
private static final String password;
//给静态常量赋值
static {
//加载属性文件并解析：
Properties props = new Properties();
//如何获得属性文件的输入流？
//通常情况使用类的加载器的方法进行获取：
InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");
try {
props.load(is);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
driverClass = props.getProperty("driverClass");
url = props.getProperty("url");
username = props.getProperty("username");
password = props.getProperty("password");
}
/**
* 注册驱动的方法
* @throws ClassNotFoundException
*/
public static void loadDriver() throws ClassNotFoundException {
Class.forName(driverClass);
}
/**
* 获得连接的方法
* @throws SQLException
*/
public static Connection getConnection() throws Exception {
loadDriver();
Connection conn = DriverManager.getConnection(url,username,password);
return conn;
}
/**
* 资源释放
*/
public static void release(Statement stmt,Connection conn) {
if(stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
stmt = null;
}
if(conn != null) {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
conn = null;
}
}
public static void release(ResultSet rs,Statement stmt,Connection conn) {
if(rs != null) {
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
rs = null;
}
if(stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
stmt = null;
}
if(conn != null) {
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
conn = null;
}
}
}
5回答
-
好帮手慕柯南
2019-11-01
同学你好！
这是同学的驱动地址写错了呢，请问同学引入的mysql的jar是什么版本的呢？如果是8.0建议同学将驱动改为：
com.mysql.cj.jdbc.Driver
如果我的回答解决了你的疑惑，请采纳，祝学习愉快~
1h019-11-01 -
weixin_慕虎6197686
2019-11-06
url的问题，"jdbc:mysql://localhost:3306/sm?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8&useSSL=false"试试这个
0 -
好帮手慕柯南
2019-11-02
同学你好！
你的url中不要添加+号呢，建议同学改为以下样子
url=jdbc:mysql://localhost:3306/jdbctest?useSSL=false&serverTimezone=Hongkong&useUnicode=true&characterEncoding=utf-8&allowPublicKeyRetrieval=true
如果我的回答解决了你的疑惑，请采纳，祝学习愉快~
0 -
XXXXg
提问者
2019-11-02
java.sql.SQLNonTransientConnectionException: Cannot load connection class because of underlying exception: com.mysql.cj.exceptions.WrongArgumentException: Failed to parse the host:port pair 'localhost:3306 +'.
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:79)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:131)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:219)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at com.imooc.jdbc.utils.JDBCUtils.getConnection(JDBCUtils.java:59)
at com.imooc.jdbc.utils.JDBCDemo3.demo1(JDBCDemo3.java:16)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at org.junit.vintage.engine.execution.RunnerExecutor.execute(RunnerExecutor.java:40)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.vintage.engine.VintageTestEngine.executeAllChildren(VintageTestEngine.java:80)
at org.junit.vintage.engine.VintageTestEngine.execute(VintageTestEngine.java:71)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:229)
at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:197)
at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:211)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:191)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:137)
at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
Caused by: com.mysql.cj.exceptions.UnableToConnectException: Cannot load connection class because of underlying exception: com.mysql.cj.exceptions.WrongArgumentException: Failed to parse the host:port pair 'localhost:3306 +'.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
... 48 more
Caused by: com.mysql.cj.exceptions.WrongArgumentException: Failed to parse the host:port pair 'localhost:3306 +'.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.conf.ConnectionUrlParser.parseHostPortPair(ConnectionUrlParser.java:502)
at com.mysql.cj.conf.ConnectionUrlParser.buildHostInfoResortingToGenericSyntaxParser(ConnectionUrlParser.java:440)
at com.mysql.cj.conf.ConnectionUrlParser.parseAuthoritySegment(ConnectionUrlParser.java:269)
at com.mysql.cj.conf.ConnectionUrlParser.parseAuthoritySection(ConnectionUrlParser.java:183)
at com.mysql.cj.conf.ConnectionUrlParser.getHosts(ConnectionUrlParser.java:632)
at com.mysql.cj.conf.ConnectionUrl.getConnectionUrlInstance(ConnectionUrl.java:198)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:196)
... 47 more
Caused by: java.lang.NumberFormatException: For input string: "3306 "
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at com.mysql.cj.conf.ConnectionUrlParser.parseHostPortPair(ConnectionUrlParser.java:500)
... 53 more
0 -
好帮手慕柯南
2019-11-02
同学你好！
在配置文件中配置时，后面不能加分号呢，建议同学将后面的分号都去掉呢
如果我的回答解决了你的疑惑，请采纳，祝学习愉快~
0h019-11-02
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