在我的 android 应用程序中，我使用以下代码复制特定表中的整个数据。但是当我检查 servlet 输出时，它似乎会生成重复值。您可以通过运行以下代码来验证这一点。我不知道为什么会这样。我需要将 servlet 中的值作为 JSON 对象传递给我的应用程序。
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.json.JSONObject;
public class vlgmas extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
// TODO output your page here
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet vlgmas</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Servlet vlgmas at " + request.getContextPath () + "</h1>");
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet Pickvalue</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Servlet Pick at " + request.getContextPath () + "</h1>");
doPost(request,response);
out.println("</body>");
out.println("</html>");
} finally
{
out.close();
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//processRequest(request, response);
String vname = null,vcode=null,divsec=null;
JSONObject obj = new JSONObject();
List list = new ArrayList();
JSONObject obj2 = new JSONObject();
PrintWriter out = response.getWriter();
String vn[]=new String[2000],vc[]=new String[2000],ds[]=new String[2000];
int t,r1=0,r2=0,r3=0;
try
{
Class.forName("oracle.jdbc.driver.OracleDriver");
java.sql.Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@192.168.1.200:1521:pdsm", "test", "test");
Statement stmt=conn.createStatement();
{
ResultSet rs = stmt.executeQuery("select * from cn_vlgmas");
while(rs.next())
{
//vn[r1++]=rs.getString ("vlgname");
//vc[r2++]=rs.getString("vlgcode");
//ds[r3++]=rs.getString("divsec");
vname=rs.getString ("vlgname");
vcode=rs.getString("vlgcode");
divsec=rs.getString("divsec");
obj.put("vname",vname);
obj.put("vcode",vcode);
obj.put("divsec",divsec);
list.add(obj);
obj2.accumulate("get", list);
out.println(obj2);
}
/*for(t=0;t<r1;t++)
{
//out.println(vn[t]+","+vc[t]+","+ds[t]+" ");
obj.put("vname",vn[t]);
obj.put("vcode",vc[t]);
obj.put("divsec",ds[t]);
list.add(obj);
//obj.append("rec", obj);
//out.println(list);
//obj.accumulate("get", list);
//out.println(obj);
obj2.accumulate("get", obj);
//out.println(obj2);
}*/
}
}catch(Exception e)
{
out.println("error"+e.toString());
}
}
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
谁能帮助我。