package com.zyj.school.util;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class DruidUtil {
/**
* 資料庫連接池中有多個連接
* 所以將con改變為DataSource
*/
// 資料源獲得資料連接源con
private static DruidDataSource datasource;
public static DataSource getDatasource() {
return datasource;
}
// 靜態塊 減少代碼量 優化代碼
static{
try {
Properties pro = readproperties();
System.out.println("Druid"+pro);
datasource = (DruidDataSource) DruidDataSourceFactory.createDataSource(pro);
System.out.println("資料庫連接成功！");
} catch (Exception e) {
e.printStackTrace();
System.out.println("資料庫連接失敗！");
}
}
// 讀方法 讀取硬碟中的ojdbc.properties檔案資訊
public static Properties readproperties() {
// 通過類加載器
InputStream inputstream = DruidUtil.class.getClassLoader().getResourceAsStream("DruidPool.properties");
// 資料型別
Properties pro = new Properties();
try {
pro.load(inputstream);
} catch (IOException e) {
e.printStackTrace();
}
return pro;
}
// 獲取連接 datasource獲得connection
public static Connection getCon() {
Connection connection = null;
try {
connection = datasource.getConnection();
} catch (SQLException e) {
e.printStackTrace();
System.out.println(e+"datasource獲得connection出現問題");
return null;
}
return connection;
}
// 關閉資料庫相關連接
public static void closeConnection(ResultSet rs,Connection conn,Statement state) throws Exception {
if(rs!=null) {
rs.close();
// System.out.println("資料庫rs關閉成功！");
}
if(state!=null) {
state.close();
// System.out.println("資料庫pstate關閉成功！");
}
if(conn!=null) {
conn.close();
// System.out.println("資料庫con關閉成功！");
}
System.out.println("資料庫關閉成功！");
}
}
java.lang.NullPointerException
at java.util.Properties$LineReader.readLine(Properties.java:434)
at java.util.Properties.load0(Properties.java:353)
at java.util.Properties.load(Properties.java:341)
at com.zyj.school.util.DruidUtil.readproperties(DruidUtil.java:44)
at com.zyj.school.util.DruidUtil.<clinit>(DruidUtil.java:28)
at com.zyj.school.dao.LoginDaoImpl.<init>(LoginDaoImpl.java:19)
at com.zyj.school.service.LoginServiceImpl.<init>(LoginServiceImpl.java:19)
at com.zyj.school.controller.LoginServlet.doPost(LoginServlet.java:36)
at com.zyj.school.controller.LoginServlet.doGet(LoginServlet.java:29)
at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:663)
at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:770)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:223)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:185)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158)
at com.zyj.school.filter.SchoolFilter.doFilter(SchoolFilter.java:24)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:185)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:353)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:870)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1696)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
資料庫連接失敗！
有沒有大佬知道這個問題應該怎么解決
uj5u.com熱心網友回復：
是不是properties的路徑不對uj5u.com熱心網友回復：
properties在resources里
uj5u.com熱心網友回復：
// 通過類加載器InputStream inputstream = DruidUtil.class.getClassLoader().getResourceAsStream("DruidPool.properties");
我的意思是你這行代碼里邊的DruidPool.properties是在src目錄下面嗎？
看下inputstream是不是null
uj5u.com熱心網友回復：
DruidPool.properties是在src目錄下面，怎么看inputstream是不是null
uj5u.com熱心網友回復：
debug除錯看啊
uj5u.com熱心網友回復：
斷點打在這行代碼上，debug進到IntrospectionUtils.class這個類里面去了，往下走會進到Digester.class這個類里，看到有好幾個值是null，我看不太懂，大佬能說一下嗎？
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