先在 web.xml 中 添加Servlet
<servlet>
<servlet-name>bingTestServlet</servlet-name>
<servlet-class>com.bing.servlet.BingTestServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>bingTestServlet</servlet-name>
<url-pattern>/abcde</url-pattern>
</servlet-mapping>
然后是servlet 类 BingTestServlet.java
package com.bing.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
public class BingTestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setStatus(200);
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
String htmlContent = "<!DOCTYPE html>\n" +
"<html lang=\"en\">\n" +
"<head>\n" +
" <meta charset=\"UTF-8\">\n" +
" <title>你好</title>\n" +
"</head>\n" +
"<body>\n" +
"<label style=\"color: red\">Hello Word !</label>\n" +
"</body>\n" +
"</html>";
writer.write(htmlContent);
writer.flush();
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
但是一般情况下，不会直接在java类里写html的代码，所以往往会在html文件里好，然后在servlet中读取里边的内容。如下：
1、首先在WEB-INF 的同级目录下，新建一个 bing.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>你好</title>
</head>
<body>
<label style="color: red">Hello Word !</label>
</body>
</html>
2、然后 将BingTestServlet.java 修改成下面代码
package com.bing.servlet;
import org.apache.commons.io.FileUtils;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
public class BingTestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private String htmlContent = null;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
if (htmlContent == null) {
String path = Thread.currentThread().getContextClassLoader().getResource("").getPath().replace("WEB-INF/classes/", "bing.html");
try {
htmlContent = FileUtils.readFileToString(new File(path), "utf-8");
} catch (Exception e) {
response.setStatus(404);
return;
}
}
response.setStatus(200);
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
writer.write(htmlContent);
writer.flush();
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
写在最后：
1、上面的例子中， /abcde 并不是一个接口，在web.xml 中被Servlet拦住了以后，就直接返回了，没有再往程序里面走
2、如果先写一个 /abcde接口，让web.xml 里先走Spring的接口，再走Servlet，将它的response修改一下，会怎么样呢？这样是不是就可以动态修改返回参数了。（当然有很多其他方法可以修改参数，这里只说servlet）
PS：发现想的幼稚了，就算有个 /abcde 的接口，断点发现，它仍然是先走Servlet， 不会走到接口里去
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原文：https://www.cnblogs.com/acm-bingzi/p/java_servlet_html.html