使用Spring MVC后实现一个BaseController

使用Spring MVC技术后，可以实现一个基类的Controller类来分装一些MVC常用的方法，其他的Controller都继承自这个BaseController，这样在使用常用的方法时将会变得非常轻松。

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原文地址：

https://www.cnblogs.com/poterliu/p/9142637.html

下面给出这个BaseController和涉及到的工具类的源码。

BaseController类

package com.xxx.yyy.portal.controller;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.web.bind.ServletRequestDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import com.xxx.yyy.portal.utils.JsonUtil;


public class BaseController {
    @InitBinder
    protected void initBinder(HttpServletRequest request, ServletRequestDataBinder binder) throws Exception {
        DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        CustomDateEditor dateEditor = new CustomDateEditor(format, true);
        binder.registerCustomEditor(Date.class, dateEditor);
        
    }
    
    public Object getAttribute(String attributeName) {
        return this.getRequest().getAttribute(attributeName);
    }

    public void setAttribute(String attributeName, Object object) {
        this.getRequest().setAttribute(attributeName, object);
    }

    public Object getSession(String attributeName) {
        return this.getRequest().getSession(true).getAttribute(attributeName);
    }

    public void setSession(String attributeName, Object object) {
        this.getRequest().getSession(true).setAttribute(attributeName, object);
    }
    
    public HttpServletRequest getRequest() {
        RequestAttributes ra = RequestContextHolder.getRequestAttributes();
        return ((ServletRequestAttributes) ra).getRequest();
    }
    
    public HttpServletResponse getResponse(){
        RequestAttributes ra = RequestContextHolder.getRequestAttributes();
        return ((ServletRequestAttributes) ra).getResponse();
    }
    
    public HttpSession getSession() {
        return this.getRequest().getSession(true);
    }
    
    public String getParameter(String paraName) {
        return this.getRequest().getParameter(paraName);
    }
    
    /**
     * 获取表单格式数据(或url拼接参数)
     * @return
     */
    @SuppressWarnings("rawtypes")
    public Map getParameterMap(){
        return this.getRequest().getParameterMap();
    }
    
    public String getHeader(String headerName) {
        return this.getRequest().getHeader(headerName);
    }
    
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public Map getHeaderMap() {
        Enumeration headerNames = this.getRequest().getHeaderNames();
        Map headerMap = new HashMap<>();
        while(headerNames.hasMoreElements()){
            String headerName = (String) headerNames.nextElement();
            String headerValue = getRequest().getHeader(headerName);
            headerMap.put(headerName, headerValue);
        }
        return headerMap;
    }
    
    public String getIpAddress(){
        String ip =  this.getRequest().getRemoteAddr();
        return ip.equals("0:0:0:0:0:0:0:1")?"127.0.0.1":ip;
    }
    
    /**
     * 获取json格式数据
     * @return
     */
    @SuppressWarnings("unchecked")
    public Map<String, Object> getRequestMap(){
        try {
            InputStream inStream = this.getRequest().getInputStream();
            //默认为json
            BufferedReader in = new BufferedReader(new InputStreamReader(inStream , "UTF-8"));
            StringBuffer stringBuffer = new StringBuffer();
            String buffer = "";
            while(null!=(buffer=(in.readLine()))){
                stringBuffer.append(buffer);
            }
            String reqDoc = stringBuffer.toString();
            if(reqDoc==null||reqDoc.equals("")){
                return null;
            }
            return JsonUtil.toMap(reqDoc) ;
        } catch (Exception e) {
           e.printStackTrace();
        }
        return null;
    }
    
    /**
     * 允许跨域访问
     */
    public void allowCrossDomainAccess(){
        HttpServletResponse servletResponse = getResponse();
        servletResponse.setHeader("Access-Control-Allow-Origin", "*");
        servletResponse.setHeader("Access-Control-Allow-Methods", "POST,GET");
        servletResponse.setHeader("Access-Control-Allow-Headers:x-requested-with", "content-type");
    }
    
}

BaseController类使用到了一个json工具类JsonUtil

package com.xxx.yyy.portal.utils;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;

import net.sf.json.JSONObject;

public class JsonUtil {

    private static final ObjectMapper mapper;

    static {
        mapper = new ObjectMapper();
        mapper.setSerializationInclusion(Include.NON_EMPTY);
        mapper.setDateFormat(new SimpleDateFormat("yyyyMMddHHmmss"));
    }

    public static <T> T json2ObjectByTr(String str, TypeReference<T> tr) 
            throws JsonParseException, JsonMappingException, IOException {
        return mapper.readValue(str, tr);
    }

    public static String Object2Json(Object obj) throws JsonProcessingException {
        return mapper.writeValueAsString(obj);
    }

    public static Map toMap(String jsonString) {
        Map result = new HashMap();
        try {
            String key = null;
            String value = null;
            JSONObject jsonObject = JSONObject.fromObject(jsonString);

            Iterator iterator = jsonObject.keys();

            while (iterator.hasNext()) {
                key = (String) iterator.next();
                value = jsonObject.getString(key);
                result.put(key, value);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
    
    public static Gson getGson(){
        Gson gson=new GsonBuilder().setDateFormat("yyyy-MM-dd").create();
        return gson;
    }
    
    public static Map fromJson(String json){
        return getGson().fromJson(json,new TypeToken<HashMap<String, Object>>(){}.getType()); 

    }
    
    public static String toJson(Object object){
        return getGson().toJson(object);
    }

}

当然了，BaseController类可以封装的方法还有很多，只要在项目的Controller中用得比较多的方法最好都封装到BaseController类中，这样不仅使用方便，提高开发效率，更重要达到了代码复用的目的，这是面向对象思想编程所推荐的。