1.统一中文编码分析
tomcat默认esetISO-8859-1编码，在servlet中，可能通过request的setCharacterEncoding(charset)和response.setContentType("text/html;charset=UTF-8");处理post请求编码,但get请求的编码控制不了，所以，如果请求类型是get，则用装饰者模式把request整个调包
2.EncodingFilter.java
1 package cn.itcast.filter;
2
3 import java.io.IOException;
4
5 import javax.servlet.Filter;
6 import javax.servlet.FilterChain;
7 import javax.servlet.FilterConfig;
8 import javax.servlet.ServletException;
9 import javax.servlet.ServletRequest;
10 import javax.servlet.ServletResponse;
11 import javax.servlet.http.HttpServletRequest;
12
13
14 public class EncodingFilter implements Filter {
15 private String charset = "UTF-8";
16 @Override
17 public void destroy() {}
18
19 @Override
20 public void doFilter(ServletRequest request, ServletResponse response,
21 FilterChain chain) throws IOException, ServletException {
22 HttpServletRequest req = (HttpServletRequest) request;
23 if(req.getMethod().equalsIgnoreCase("GET")) {
24 if(!(req instanceof GetRequest)) {
25 req = new GetRequest(req, charset);//处理get请求编码
26 }
27 } else {
28 req.setCharacterEncoding(charset);//处理post请求编码
29 }
30 chain.doFilter(req, response);
31 }
32
33 @Override
34 public void init(FilterConfig fConfig) throws ServletException {
35 String charset = fConfig.getInitParameter("charset");
36 if(charset != null && !charset.isEmpty()) {
37 this.charset = charset;
38 }
39 }
40 }
3.GetRequest.java 装饰者模式
1 package cn.itcast.filter;
2
3 import java.io.UnsupportedEncodingException;
4 import java.util.Enumeration;
5 import java.util.Map;
6 import javax.servlet.http.HttpServletRequest;
7 import javax.servlet.http.HttpServletRequestWrapper;
8
9 /**
10 * 对GET请求参数加以处理！
11 * @author qdmmy6
12 *
13 */
14 public class GetRequest extends HttpServletRequestWrapper {
15 private HttpServletRequest request;
16 private String charset;
17
18 public GetRequest(HttpServletRequest request, String charset) {
19 super(request);
20 this.request = request;
21 this.charset = charset;
22 }
23
24 @Override
25 public String getParameter(String name) {
26 // 获取参数
27 String value = request.getParameter(name);
28 if(value == null) return null;//如果为null，直接返回null
29 try {
30 // 对参数进行编码处理后返回
31 return new String(value.getBytes("ISO-8859-1"), charset);
32 } catch (UnsupportedEncodingException e) {
33 throw new RuntimeException(e);
34 }
35 }
36
37 @SuppressWarnings({ "unchecked", "rawtypes" })
38 @Override
39 public Map getParameterMap() {
40 Map<String,String[]> map = request.getParameterMap();
41 if(map == null) return map;
42 // 遍历map，对每个值进行编码处理
43 for(String key : map.keySet()) {
44 String[] values = map.get(key);
45 for(int i = 0; i < values.length; i++) {
46 try {
47 values[i] = new String(values[i].getBytes("ISO-8859-1"), charset);
48 } catch (UnsupportedEncodingException e) {
49 throw new RuntimeException(e);
50 }
51 }
52 }
53 // 处理后返回
54 return map;
55 }
56
57 @Override
58 public String[] getParameterValues(String name) {
59 String[] values = super.getParameterValues(name);
60 for(int i = 0; i < values.length; i++) {
61 try {
62 values[i] = new String(values[i].getBytes("ISO-8859-1"), charset);
63 } catch (UnsupportedEncodingException e) {
64 throw new RuntimeException(e);
65 }
66 }
67 return values;
68 }
69 }
3.BaseServlet.java
1 package cn.itcast.servlet;
2
3 import java.io.IOException;
4 import java.lang.reflect.Method;
5
6 import javax.servlet.ServletException;
7 import javax.servlet.http.HttpServlet;
8 import javax.servlet.http.HttpServletRequest;
9 import javax.servlet.http.HttpServletResponse;
10
11 /**
12 * BaseServlet用来作为其它Servlet的父类
13 *
14 * @author qdmmy6
15 *
16 * 一个类多个请求处理方法，每个请求处理方法的原型与service相同！ 原型 = 返回值类型 + 方法名称 + 参数列表
17 */
18 @SuppressWarnings("serial")
19 public class BaseServlet extends HttpServlet {
20 @Override
21 public void service(HttpServletRequest request, HttpServletResponse response)
22 throws ServletException, IOException {
23 response.setContentType("text/html;charset=UTF-8");//处理响应编码
24
25 /**
26 * 1. 获取method参数，它是用户想调用的方法 2. 把方法名称变成Method类的实例对象 3. 通过invoke()来调用这个方法
27 */
28 String methodName = request.getParameter("method");
29 Method method = null;
30 /**
31 * 2. 通过方法名称获取Method对象
32 */
33 try {
34 method = this.getClass().getMethod(methodName,
35 HttpServletRequest.class, HttpServletResponse.class);
36 } catch (Exception e) {
37 throw new RuntimeException("您要调用的方法：" + methodName + "它不存在！", e);
38 }
39
40 /**
41 * 3. 通过method对象来调用它
42 */
43 try {
44 String result = (String)method.invoke(this, request, response);
45 if(result != null && !result.trim().isEmpty()) {//如果请求处理方法返回不为空
46 int index = result.indexOf(":");//获取第一个冒号的位置
47 if(index == -1) {//如果没有冒号，使用转发
48 request.getRequestDispatcher(result).forward(request, response);
49 } else {//如果存在冒号
50 String start = result.substring(0, index);//分割出前缀
51 String path = result.substring(index + 1);//分割出路径
52 if(start.equals("f")) {//前缀为f表示转发
53 request.getRequestDispatcher(path).forward(request, response);
54 } else if(start.equals("r")) {//前缀为r表示重定向
55 response.sendRedirect(request.getContextPath() + path);
56 }
57 }
58 }
59 } catch (Exception e) {
60 throw new RuntimeException(e);
61 }
62 }
63 }
时间： 2024-10-11 17:20:23