Java 连接Mysql 加载 直接写Class.forName("com.mysql.jdbc.Driver"); 可以成功，但读properties Class.forName(drivers);）; drivers = props.getProperty("driver“”（ System.out.println(drivers)也可打印com.mysql.jdbc.Driver成功证明取到了 "); 就失败报java.lang.ClassNotFoundException: com.mysql.jdbc.Driver 读url user passw读到可打印 但就是报错都是 具体代码如下ord
private void init() {
try {
// InputStream in = getClass().getResourceAsStream(FILE_PATH_NAME);
InputStream in = DataConnection.class.getClassLoader().getResourceAsStream(FILE_PATH_NAME);
Properties props = new Properties();
props.load(in);
in.close();
drivers = props.getProperty("driver");
url = props.getProperty("url");
username = props.getProperty("username");
password = props.getProperty("password");
} catch (IOException e) {
e.printStackTrace();
}
}
public Connection getConnection() {
Connection conn = null;
try {
System.out.println(drivers);
Class.forName(drivers);
// System.out.println("com.mysql.jdbc.Driver");
// Class.forName("com.mysql.jdbc.Driver");
// conn = DriverManager.getConnection(url, username, password);
conn = DriverManager.getConnection("jdbc:mysql://10.5.0.20/robottest","root", "1234");
} catch (SQLException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return conn;
}
报错
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1856)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1705)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:171)
at dao.DataConnection.getConnection(DataConnection.java:53)
at org.apache.jsp.connTest_jsp._jspService(connTest_jsp.java:120)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at com.atguigu.javaweb.AuthorityFilter.doFilter(AuthorityFilter.java:29)
at com.atguigu.javaweb.HttpFilter.doFilter(HttpFilter.java:59)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:662)
