java - 由于 web.xml 或 servlet.java,本地主机上的服务器 Tomcat v8.5 服务器无法启动 Eclipse
问题描述
我正在构建一个简单的动态 Web 应用程序来显示给定地点的天气。最初,它运行良好,但是当我创建 servlet 时,tomcat 服务器没有启动。我正在附加我项目中的所有文件。任何帮助,将不胜感激。
- 主页.html
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1>About</h1> <br>
My introduction.....
<form action="geolocation.html">
<input type="submit" value="Go to geolocation page" />
</form>
</body>
</html>
- 地理位置.html
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1>GeoLocation Page</h1> <br>
<form action="/abc" method="GET">
Enter the place: <input type="text" name="place" > <br>
<input type= "submit" value="submit">
</form>
</body>
</html>
- Servlet1.java
package pack1;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.*;
/**
* Servlet implementation class servlet1
*/
@WebServlet("/servlet1")
public class servlet1 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public servlet1() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/plain;charset=UTF-8");
String place= request.getParameter("place");
BufferedReader br = null;
String query;
try {
URL url = new URL("https://api.mapbox.com/geocoding/v5/mapbox.places/"+place+".json?access_token=pk.eyJ1IjoidmlwaW5jIiwiYSI6ImNrYjlpdWs1NjBlZjczM2pwd2R6Y3o5djkifQ.ULsLgK5_7oQ8Vf3JHhnnig");
br = new BufferedReader(new InputStreamReader(url.openStream()));
String line;
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line);
sb.append(System.lineSeparator());
}
// System.out.println(sb);
query = sb.toString();
} finally {
if (br != null) {
br.close();
}
}
int index=query.indexOf("coordinates");
query = query.substring(index,index+32);
int index1 = query.indexOf("[");
int index2 = query.indexOf("]");
query = query.substring(index1+1,index2);
double latitude,longitude;
String s1,s2;
s1 = query.substring(0,query.length()/2);
s2 = query.substring(query.length()/2+1,query.length());
longitude= Double.parseDouble(s1);
latitude = Double.parseDouble(s2);
try {
URL url = new URL("http://api.openweathermap.org/data/2.5/weather?lat="+latitude+"&lon="+longitude+"&appid=370084bf98bc2a7fd4e580302b642c42");
br = new BufferedReader(new InputStreamReader(url.openStream()));
String line;
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line);
sb.append(System.lineSeparator());
}
// System.out.println(sb);
query = sb.toString();
} finally {
if (br != null) {
br.close();
}
}
Object obj = null;
try {
obj = new JSONParser().parse(query);
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// typecasting obj to JSONObject
JSONObject jo = (JSONObject) obj;
String name = (String) jo.get("name");
System.out.println("name="+name);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
- web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>foo</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>
解决方案
注意: 类名应以大写字符开头。
您应该在发送请求的web.xml中 映射自定义 servlet 类。
正确的web.xml应该是:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>foo</display-name>
<servlet>
<servlet-name>Servlet1</servlet-name>
<servlet-class>package.Servlet1</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Servlet1</servlet-name>
<url-pattern>/servlet1</url-pattern>
</servlet-mapping>
</web-app>
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