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從另一個servlet表單標簽調用servlet

[英]Call servlet from another servlet form tag

我有一個帶有表單標簽的Servlet。 在此表單標簽中,我想調用另一個servlet。

out.println("<form id=\"myform\" action='/SubmitHome' method=\"post\">");

因此,當我單擊提交按鈕時:

out.println("<input type=\"submit\" name=\"assignButton\" value=\"Assign\" />

它沒有調用“ / SubmitHome”。

知道為什么不打電話嗎?

請檢查您的HTML,標記是否正確關閉? 例如

<form action="" method="post">
<input type="submit" value="Submit">
</form>

Sytanx對於以下行是錯誤的(您需要完成println大括號:

out.println("<input type=\\"submit\\" name=\\"assignButton\\" value=\\"Assign\\" />

應該

out.println("<input type=\\"submit\\" name=\\"assignButton\\" value=\\"Assign\\" />");

其他一切都完美無缺,並且運作良好:)

這是完成任務的示例代碼。

步驟1:創建一個Servlet。

    package org.smarttechie;

    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;

    /**
     * Servlet implementation class SampleServlet1
     */
    public class SampleServlet1 extends HttpServlet {
        private static final long serialVersionUID = 1L;

        /**
         * @see HttpServlet#HttpServlet()
         */
        public SampleServlet1() {
            super();
            // TODO Auto-generated constructor stub
        }

        /**
         * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
         */
        protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            PrintWriter out = response.getWriter();
            out.println("<html><body>");
            out.println("<form action=\"SampleServlet2\" method=\"get\">");
            out.println("<input type=\"submit\" value=\"Submit\">");
            out.println("</form>");
            out.println("</body></html>");
        }
    }

步驟2:創建另一個Servlet。 這將從表單操作標簽中調用。 如果您觀察到表單操作標簽值,則指向“ SampleServlet2” URL模式(不包括“ /”)。 如果要給出絕對路徑(包括“ /”),我們需要指定上下文路徑。

package org.smarttechie;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class SampleServlet2
 */
public class SampleServlet2 extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public SampleServlet2() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("The request is reached");
    }

}

步驟3:web.xml配置如下。

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <servlet>
    <description></description>
    <display-name>SampleServlet1</display-name>
    <servlet-name>SampleServlet1</servlet-name>
    <servlet-class>org.smarttechie.SampleServlet1</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>SampleServlet1</servlet-name>
    <url-pattern>/SampleServlet1</url-pattern>
  </servlet-mapping>
  <servlet>
    <description></description>
    <display-name>SampleServlet2</display-name>
    <servlet-name>SampleServlet2</servlet-name>
    <servlet-class>org.smarttechie.SampleServlet2</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>SampleServlet2</servlet-name>
    <url-pattern>/SampleServlet2</url-pattern>
  </servlet-mapping>
</web-app>

希望這能解決您的問題。

您應該檢查web.xml中的url映射,這是表單未在所需頁面上提交的唯一原因。

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