資源簡介
在使用Java程序從數據庫中查詢大量的數據或是應用服務器(如tomcat、jboss,weblogic)加載jar包時會出現java.lang.OutOfMemoryError異常。這主要是由于應用服務器的內存不足引起的。

代碼片段和文件信息
package?ctrl;
import?java.util.regex.*;
import?java.io.IOException;
import?java.io.PrintWriter;
import?java.sql.Connection;
import?java.sql.DriverManager;
import?java.sql.PreparedStatement;
import?java.sql.ResultSet;
import?java.sql.SQLException;
import?java.util.Vector;
import?javax.servlet.RequestDispatcher;
import?javax.servlet.ServletContext;
import?javax.servlet.ServletException;
import?javax.servlet.http.HttpServlet;
import?javax.servlet.http.HttpServletRequest;
import?javax.servlet.http.HttpServletResponse;
import?javax.servlet.http.HttpSession;
import?data.DatabaseOp;
import?data.Staff;
public?class?ReceiveData?extends?HttpServlet?{
/**
?*?Constructor?of?the?object.
?*/
public?ReceiveData()?{
super();
}
/**
?*?Destruction?of?the?servlet.?
?*/
public?void?destroy()?{
super.destroy();?//?Just?puts?“destroy“?string?in?log
//?Put?your?code?here
}
/**
?*?The?doGet?method?of?the?servlet.?
?*
?*?This?method?is?called?when?a?form?has?its?tag?value?method?equals?to?get.
?*?
?*?@param?request?the?request?send?by?the?client?to?the?server
?*?@param?response?the?response?send?by?the?server?to?the?client
?*?@throws?ServletException?if?an?error?occurred
?*?@throws?IOException?if?an?error?occurred
?*/
public?void?doGet(HttpServletRequest?request?HttpServletResponse?response)
throws?ServletException?IOException?{
DatabaseOp?data=new?DatabaseOp();
//顯示記錄
System.out.println(request.getParameter(“OP“));
System.out.print( request.getParameter(“ID“));
if(request.getParameter(“OP“).equals(“show“))
{ String?id=request.getParameter(“ID“);
????Staff?staff=?data.showStaff(id);
????request.setAttribute(“staffnow“?staff);
????ServletContext??sc?=?getServletContext();
????System.out.print(staff.getName());
????RequestDispatcher?rd=sc.getRequestDispatcher(“/data.jsp“);
????rd.forward(request?response);
????
????
????
????
????
????
????
????
response.setContentType(“text/html“);
PrintWriter?out?=?response.getWriter();
out
.println(““);
out.println(““);
out.println(“??tle>A?Servlet tle>“);
out.println(“??“);
out.print(“????This?is?“);
out.print(staff.getName());
out.print(this.getClass());
out.print(id);
out.println(“?using?the?GET?method“);
out.println(“??“);
out.println(““);
out.flush();
out.close();
}
//刪除記錄
else if(request.getParameter(“OP“).equals(“delete“)){
????????String?id=request.getParameter(“ID“);
????????data.deletStuff(id);
????????ServletContext??sc?=?getServletContext();
???? ????
???? ????RequestDispatcher?rd=sc.getRequestDispatcher(“/main.jsp“);
???? ????rd.forward(request?response);
????????}
???????else???if(request.getParameter(“OP“).equals(“modify“)){
????????????String?id=request.getParameter(“ID“);
?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????433??2007-07-10?15:36??contacts\.classpath
?????文件????????297??2007-07-10?15:09??contacts\.myme
?????文件???????1256??2007-07-10?16:32??contacts\.project
?????文件????????137??2007-07-10?15:35??contacts\.settings\org.eclipse.ltk.core.refactoring.prefs
?????文件???????2285??2007-07-11?08:52??contacts\data?20070711?0851.sql
?????文件??????14584??2007-07-12?19:09??contacts\src\ctrl\ReceiveData.java
?????文件???????4438??2007-07-12?09:45??contacts\src\data\Databa
?????文件???????1367??2007-07-12?13:15??contacts\src\data\Staff.java
?????文件???????3209??2007-07-12?16:06??contacts\WebRoot\add.jsp
?????文件???????5233??2007-07-10?16:02??contacts\WebRoot\bg.jpg
?????文件???????8324??2007-07-10?16:02??contacts\WebRoot\bgg.jpg
?????文件????1073655??2007-07-12?16:27??contacts\WebRoot\contacts.war
?????文件???????4160??2007-07-12?18:58??contacts\WebRoot\data.jsp
?????文件????????657??2007-07-12?16:11??contacts\WebRoot\index.jsp
?????文件???????1015??2007-07-12?16:12??contacts\WebRoot\main.jsp
?????文件?????????39??2007-07-10?15:09??contacts\WebRoot\me
?????文件??????????0??2007-07-12?09:04??contacts\WebRoot\refresh.js
?????文件????????853??2007-07-12?13:23??contacts\WebRoot\result.jsp
?????文件????????521??2007-07-12?17:46??contacts\WebRoot\uf4.jsp
?????文件???????9954??2007-07-12?18:12??contacts\WebRoot\Unti
?????文件???????7967??2007-07-12?19:09??contacts\WebRoot\WEB-INF\classes\ctrl\ReceiveData.class
?????文件???????4389??2007-07-12?11:43??contacts\WebRoot\WEB-INF\classes\data\Databa
?????文件???????2104??2007-07-12?13:15??contacts\WebRoot\WEB-INF\classes\data\Staff.class
?????文件?????527090??2007-05-15?19:38??contacts\WebRoot\WEB-INF\lib\mysql-connector-java-5.0.6-bin.jar
?????文件????????711??2007-07-10?16:08??contacts\WebRoot\WEB-INF\web.xm
?????目錄??????????0??2007-07-12?11:43??contacts\WebRoot\WEB-INF\classes\ctrl
?????目錄??????????0??2007-07-12?11:43??contacts\WebRoot\WEB-INF\classes\data
?????目錄??????????0??2007-07-12?11:43??contacts\WebRoot\WEB-INF\classes
?????目錄??????????0??2007-07-10?15:36??contacts\WebRoot\WEB-INF\lib
?????目錄??????????0??2007-07-10?16:08??contacts\src\ctrl
............此處省略10個文件信息
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