真的急用,调试不出来,我写的Bean一定有问题
代码如下:(test.jsp文件)
<%@ page language="java" import="java.sql.*" %>
<jsp:useBean id="test" scope="page" class="web.jndiconn" />
<%
String SQL="select * from user";
Connection file_conn =test.getConnection();
Statement cons_stmt = file_conn.createStatement();
ResultSet Rs=cons_stmt.executeQuery(SQL);
try
{
Rs.last();
}
catch(SQLException e)
{
System.err.print("移动记录时发生错误!");
}
%>
//-------------javabean代码如下(jndiconn.java):------------------
//备注:编译调试通过,可生成CLASS文件
package web;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
public class jndiconn
{
static String jndiName="TestDB";
private Context initCtx = null;
private Context ctx = null;
private Object obj = null;
private DataSource ds = null;
private Connection conn = null;
private Statement stmt = null;
private ResultSet rs = null; public jndiconn()
{
try {
initCtx = new InitialContext();
ctx = (Context) initCtx.lookup("java:comp/env");
obj = (Object) ctx.lookup(jndiName);
ds = (DataSource)obj;
}
catch(Exception e){
e.printStackTrace();
//throw e;
}
} public Connection getConnection() throws Exception
{
conn = null;
try {
conn = ds.getConnection();
}
catch(Exception e){
e.printStackTrace();
throw e;
}
return conn;
} public Statement createStatement()
{
stmt = null;
try {
stmt = conn.createStatement();
}
catch(SQLException ex) {
System.err.println("ResultSet.executeQuery: " + ex.getMessage());
}
return stmt;
}
//执行SQL命令,并返回记录集
public ResultSet executeQuery(String sql)
{
rs = null;
try {
rs = stmt.executeQuery(sql);
}
catch(SQLException ex) {
System.err.println("ResultSet.executeQuery: " + ex.getMessage());
}
return rs;
}
//执行SQL命令,更新数据库,但不返回任何数值
public void executeUpdate(String sql)
{
stmt = null;
rs=null;
try {
stmt.executeQuery(sql);
stmt.close();
conn.close();
}
catch(SQLException ex) {
System.err.println("ResultSet.executeQuery: " + ex.getMessage());
}
}
}
//------------------备注:数据库连接池部分已经测试正常-----------
//------------------运行JSP文件,错误提示如下:------------------
java.lang.OutOfMemoryError: Java heap space
我该如何修改我的JAVA文件?
代码如下:(test.jsp文件)
<%@ page language="java" import="java.sql.*" %>
<jsp:useBean id="test" scope="page" class="web.jndiconn" />
<%
String SQL="select * from user";
Connection file_conn =test.getConnection();
Statement cons_stmt = file_conn.createStatement();
ResultSet Rs=cons_stmt.executeQuery(SQL);
try
{
Rs.last();
}
catch(SQLException e)
{
System.err.print("移动记录时发生错误!");
}
%>
//-------------javabean代码如下(jndiconn.java):------------------
//备注:编译调试通过,可生成CLASS文件
package web;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
public class jndiconn
{
static String jndiName="TestDB";
private Context initCtx = null;
private Context ctx = null;
private Object obj = null;
private DataSource ds = null;
private Connection conn = null;
private Statement stmt = null;
private ResultSet rs = null; public jndiconn()
{
try {
initCtx = new InitialContext();
ctx = (Context) initCtx.lookup("java:comp/env");
obj = (Object) ctx.lookup(jndiName);
ds = (DataSource)obj;
}
catch(Exception e){
e.printStackTrace();
//throw e;
}
} public Connection getConnection() throws Exception
{
conn = null;
try {
conn = ds.getConnection();
}
catch(Exception e){
e.printStackTrace();
throw e;
}
return conn;
} public Statement createStatement()
{
stmt = null;
try {
stmt = conn.createStatement();
}
catch(SQLException ex) {
System.err.println("ResultSet.executeQuery: " + ex.getMessage());
}
return stmt;
}
//执行SQL命令,并返回记录集
public ResultSet executeQuery(String sql)
{
rs = null;
try {
rs = stmt.executeQuery(sql);
}
catch(SQLException ex) {
System.err.println("ResultSet.executeQuery: " + ex.getMessage());
}
return rs;
}
//执行SQL命令,更新数据库,但不返回任何数值
public void executeUpdate(String sql)
{
stmt = null;
rs=null;
try {
stmt.executeQuery(sql);
stmt.close();
conn.close();
}
catch(SQLException ex) {
System.err.println("ResultSet.executeQuery: " + ex.getMessage());
}
}
}
//------------------备注:数据库连接池部分已经测试正常-----------
//------------------运行JSP文件,错误提示如下:------------------
java.lang.OutOfMemoryError: Java heap space
我该如何修改我的JAVA文件?
解决方案 »
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