版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/qq_34598667/article/details/88967996
1)新建EncodingFilter过滤器
新建过滤器过去所有请求,用于处理请求参数的解码方式为UTF-8,解决中文乱码
/**
* 统一编码
* @author Administrator
*/
@WebFilter("/*")//过滤所有路径
public class EncodingFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub
}
@Override
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException {
//1.强转
HttpServletRequest request=(HttpServletRequest) req;
HttpServletResponse response=(HttpServletResponse) resp;
//2.放行
chain.doFilter(request, response);
}
@Override
public void destroy() {
// TODO Auto-generated method stub
}
}
2)自定义请求继承HttpServletRequestWrapper
HttpServletRequestWrapper实现了HttpServletRequest接口,自己写类继承HttpServletRequestWrapper,然后实现重写其中的String getParameter(String name)、String[] getParameterValues(String name)、String[] getParameterValues(String name)三个方法。它们就可以根据我们的需求做改变,比如设置字符,去掉空格。
在EncodingFilter文件中创建类MyRequest:
class MyRequest extends HttpServletRequestWrapper{
private HttpServletRequest request;
private boolean flag=true;
public MyRequest(HttpServletRequest request) {
super(request);
this.request=request;
}
@Override
public String getParameter(String name) {
if(name==null || name.trim().length()==0){
return null;
}
String[] values = getParameterValues(name);
if(values==null || values.length==0){
return null;
}
return values[0];
}
@Override
/**
* hobby=[eat,drink]
*/
public String[] getParameterValues(String name) {
if(name==null || name.trim().length()==0){
return null;
}
Map<String, String[]> map = getParameterMap();
if(map==null || map.size()==0){
return null;
}
return map.get(name);
}
@Override
/**
* map{ username=[tom],password=[123],hobby=[eat,drink]}
*/
public Map<String,String[]> getParameterMap() {
/**
* 首先判断请求方式
* 若为post request.setchar...(utf-8)
* 若为get 将map中的值遍历编码就可以了
*/
String method = request.getMethod();
if("post".equalsIgnoreCase(method)){
try {
request.setCharacterEncoding("utf-8");
return request.getParameterMap();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else if("get".equalsIgnoreCase(method)){
Map<String,String[]> map = request.getParameterMap();
//需要遍历map 修改value的每一个数据的编码
if(flag){
for (String key:map.keySet()) {
String[] arr = map.get(key);
//继续遍历数组
for(int i=0;i<arr.length;i++){
//编码
try {
arr[i]=new String(arr[i].getBytes("iso8859-1"),"utf-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
}
flag=false;
}
return map;
}
return super.getParameterMap();
}
}
3)过滤器中使用自定义请求完成编码的设置
...
//2.放行
chain.doFilter(new MyRequest(request), response);
...
这样一来,在servlet中调用包装器的getParameters方法来获取参数,就已经完成了字符编码的转换过程,我们就不需要在每次获取参数时来进行字符编码转换了。
4)测试注册
查看数据库: