servlet之间的数据传递
1：如何让用户的请求数据从一个Servlet传递给另一个Servlet
第一种方式：通过超链接传递数据
第二种方式：通过表传递取参数。
第三种方式：通过setAttribute("name",value)与getAttribute(name value)传递参数
1)通过超链接获得参数：
需要在超链接后面给定要传递参数的值。但长度有限制
Java代码
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestA extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out=response.getWriter();
String name="hello,everyone";
out.println("<html>");
out.println("<body>");
out.println("<a href='/JSP/test?id="+name+"'>this is a test</a>");
out.println("<body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestA extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out=response.getWriter();
String name="hello,everyone";
out.println("<html>");
out.println("<body>");
out.println("<a href='/JSP/test?id="+name+"'>this is a test</a>");
out.println("<body>");
out.println("</html>");
out.flush();
}
}
通过request.getParameter("id")获得参数的值：
Java代码
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name=request.getParameter("id");
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name=request.getParameter("id");
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
通过表单获得参数：
Java代码
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TableP extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println("<form action='/JSP/tabletest' method='post'>");
out.println("<table align='center'>");
out.println("<tr>");
out.println("<td>");
out.println("username:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='name'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>");
out.println("password:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='pwd'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr >");
out.println("<td colspan='2'>");
out.println("<input type='submit' value='提交'>");
out.println("</td>");
out.println("</tr>");
out.println("</table>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GetTableP extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html;charset=gb2312");
PrintWriter out=resp.getWriter();
String name=req.getParameter("name");
String pwd=req.getParameter("pwd");
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("<hr>");
out.println(pwd);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TableP extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println("<form action='/JSP/tabletest' method='post'>");
out.println("<table align='center'>");
out.println("<tr>");
out.println("<td>");
out.println("username:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='name'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>");
out.println("password:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='pwd'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr >");
out.println("<td colspan='2'>");
out.println("<input type='submit' value='提交'>");
out.println("</td>");
out.println("</tr>");
out.println("</table>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GetTableP extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html;charset=gb2312");
PrintWriter out=resp.getWriter();
String name=req.getParameter("name");
String pwd=req.getParameter("pwd");
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("<hr>");
out.println(pwd);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
3：通过setAttribute("name",data)和getAttribute("name");
其中data可以是任何数据类型，另一个servlet通过名字获取该对象getAttribute("name");
注：setAttriute可以被request,session,ServletContext等对象使用。以下以request为例：
Java代码
package testParameter;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AttributeA extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String data="this is just a test,wo need more test for this";
req.setAttribute("name", data);
req.getRequestDispatcher("/attributeb").forward(req, resp);
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AttributeB extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String name=(String)req.getAttribute("name");
resp.setContentType("text/html;charset=gb2312");
PrintWriter out=resp.getWriter();
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
第一种方式：通过超链接传递数据
第二种方式：通过表传递取参数。
第三种方式：通过setAttribute("name",value)与getAttribute(name value)传递参数
1)通过超链接获得参数：
需要在超链接后面给定要传递参数的值。但长度有限制
Java代码
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestA extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out=response.getWriter();
String name="hello,everyone";
out.println("<html>");
out.println("<body>");
out.println("<a href='/JSP/test?id="+name+"'>this is a test</a>");
out.println("<body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TestA extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out=response.getWriter();
String name="hello,everyone";
out.println("<html>");
out.println("<body>");
out.println("<a href='/JSP/test?id="+name+"'>this is a test</a>");
out.println("<body>");
out.println("</html>");
out.flush();
}
}
通过request.getParameter("id")获得参数的值：
Java代码
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name=request.getParameter("id");
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String name=request.getParameter("id");
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
通过表单获得参数：
Java代码
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TableP extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println("<form action='/JSP/tabletest' method='post'>");
out.println("<table align='center'>");
out.println("<tr>");
out.println("<td>");
out.println("username:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='name'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>");
out.println("password:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='pwd'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr >");
out.println("<td colspan='2'>");
out.println("<input type='submit' value='提交'>");
out.println("</td>");
out.println("</tr>");
out.println("</table>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GetTableP extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html;charset=gb2312");
PrintWriter out=resp.getWriter();
String name=req.getParameter("name");
String pwd=req.getParameter("pwd");
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("<hr>");
out.println(pwd);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class TableP extends HttpServlet{
@Override
protected void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<body>");
out.println("<form action='/JSP/tabletest' method='post'>");
out.println("<table align='center'>");
out.println("<tr>");
out.println("<td>");
out.println("username:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='name'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td>");
out.println("password:");
out.println("</td>");
out.println("<td>");
out.println("<input type='text' name='pwd'>");
out.println("</td>");
out.println("</tr>");
out.println("<tr >");
out.println("<td colspan='2'>");
out.println("<input type='submit' value='提交'>");
out.println("</td>");
out.println("</tr>");
out.println("</table>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
out.flush();
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class GetTableP extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
resp.setContentType("text/html;charset=gb2312");
PrintWriter out=resp.getWriter();
String name=req.getParameter("name");
String pwd=req.getParameter("pwd");
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("<hr>");
out.println(pwd);
out.println("</body>");
out.println("</html>");
out.flush();
}
}
3：通过setAttribute("name",data)和getAttribute("name");
其中data可以是任何数据类型，另一个servlet通过名字获取该对象getAttribute("name");
注：setAttriute可以被request,session,ServletContext等对象使用。以下以request为例：
Java代码
package testParameter;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AttributeA extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String data="this is just a test,wo need more test for this";
req.setAttribute("name", data);
req.getRequestDispatcher("/attributeb").forward(req, resp);
}
}
package testParameter;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AttributeB extends HttpServlet{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String name=(String)req.getAttribute("name");
resp.setContentType("text/html;charset=gb2312");
PrintWriter out=resp.getWriter();
out.println("<html>");
out.println("<body>");
out.println(name);
out.println("</body>");
out.println("</html>");
out.flush();
}
}