JSP编译错误，无法运行，求哪位好心人帮解决一下

<%@ page language="java" contentType="text/html; charset=gb2312"
    pageEncoding="gb2312"%>
    
    <%@ page import="java.sql.*" %>
<%@ page import="hello.*" %>   <%!
String str = "";
private void tree (Connection conn, int id, int level){
Statement stmt = null;
ResultSet rs = null;
String preStr = "";
for(int i = 0;i < level;i++){
preStr = preStr + "----";
}
try{
stmt = conn.createStatement();
String sql = "select * from article where pid = "+id;
rs = stmt.executeQuery(sql);
while(rs.next()){
str += "<tr><td>"+rs.getInt("id")+"</td><td>" + preStr +rs.getString("cont")+"</td></tr>";
if(rs.getInt("isleaf") != 0){
tree(conn,rs.getInt(id),level+1);
}
}
}catch(SQLException e){
e.printStackTrace();
}finally{
try{
if(rs != null){
rs.close();
}
if(stmt != null){
stmt.close();
}
if(conn != null){
conn.close();
}
}catch(SQLException e){
e.printStackTrace();
}
}
}
%><%
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost/bbs?user=root&password=sang";
Connection conn = DriverManager.getConnection(url);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select * from article where pid = 0");
while(rs.next()){
str += "<tr><td>" + rs.getInt("id") + "</td><td>" + rs.getString("cont") + "</td><tr>";
if(rs.getInt("isleaf") != 0){
tree(conn,rs.getInt("id"),1);
}
}
%>
<%
rs.close();
stmt.close();
conn.close();
%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Insert title here</title>
</head>
<body>
<table>
<%=str %>
</table>
</body>
</html>下面是报的错误：HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /ShowArticleTree.jsp at line 2118:  String sql = "select * from article where pid = "+id;
19:  rs = stmt.executeQuery(sql);
20:  while(rs.next()){
21:  str += "<tr><td>"+rs.getInt("id")+"</td><td>" + preStr +rs.getString("cont")+"</td></tr>";
22:  if(rs.getInt("isleaf") != 0){
23:  tree(conn,rs.getInt(id),level+1);
24:  }
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:568)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:455)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause javax.servlet.ServletException: java.lang.OutOfMemoryError: Java heap space
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:911)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:840)
org.apache.jsp.ShowArticleTree_jsp._jspService(ShowArticleTree_jsp.java:150)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause java.lang.OutOfMemoryError: Java heap space
java.util.Arrays.copyOf(Unknown Source)
java.lang.AbstractStringBuilder.expandCapacity(Unknown Source)
java.lang.AbstractStringBuilder.append(Unknown Source)
java.lang.StringBuilder.append(Unknown Source)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:34)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
org.apache.jsp.ShowArticleTree_jsp.tree(ShowArticleTree_jsp.java:36)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.23 logs.
--------------------------------------------------------------------------------Apache Tomcat/7.0.23

解决方案 »

  1.   

    java.lang.OutOfMemoryError: Java heap space
      

  2.   

    org.apache.jasper.JasperException: An exception occurred processing JSP page /ShowArticleTree.jsp at line 21
      

  3.   

    java.lang.OutOfMemoryError: Java heap space 堆溢出
    org.apache.jasper.JasperException: An exception occurred processing JSP page /ShowArticleTree.jsp at line 21 /ShowArticleTree.jsp 21行出错。
    死循环了？
      

  4.   

    private void tree (Connection conn, int id, int level){->??jsp中定义方法是不行的??
     
      

  5.   

    内存溢出了，应该是你fetch的数据太多了，尝试将数据分段处理，或者增大JVM的内存
      

  6.   

    str += "<tr><td>"+rs.getInt("id")+"</td><td>" + preStr +rs.getString("cont")+"</td></tr>";
    你为啥不直接输出呢