使用 Spring MVC 后实现一个 BaseController 和 JsonUtil

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。

 

需要在 maven 中引入的 依赖包如下：

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.4.2</version>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.11</version>
        </dependency>

        <!--json-->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.6</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.11.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.11.3</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.11.3</version>
        </dependency>
        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
        </dependency>

 

 

下面给出这个BaseController和涉及到的工具类的源码。

BaseController类

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.UnknownHostException;
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.apache.commons.lang3.StringUtils;
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.pbm.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;
        HttpServletRequest request = getRequest();
        String ip = request.getHeader("X-Forwarded-For");
        if (StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            int index = ip.indexOf(",");
            if (index != -1) {
                return ip.substring(0, index);
            } else {
                return ip;
            }
        }
        ip = request.getHeader("X-Real-IP");
        if (StringUtils.isNotEmpty(ip) && !"unKnown".equalsIgnoreCase(ip)) {
            return ip;
        }
        return request.getRemoteAddr();
    }
    
    /** * 获取服务器ip地址 * @return */
    public String getServerIpAddress() {
        InetAddress address;
        String serverIpAddress = null;
        try {
            address = InetAddress.getLocalHost(); // 获取的是本地的IP地址
            // PC-20140317PXKX/192.168.0.121
            serverIpAddress = address.getHostAddress();// 192.168.0.121
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
        return serverIpAddress;
    }
    
    /** * 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.poterliu.util;

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"));
    }

    /**
     * 调用格式示范：
     * JsonUtil.json2ObjectByTr(jsonStr, new TypeReference<List<Map>>() {})
     */
    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);
    }

    /**
     * 全部使用 json2ObjectByTr 方法进行转换，此方法已过时，容易造成类型转换错误
     */
    @Deprecated
    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。

 

 

原文地址：

https://www.cnblogs.com/poterliu/p/9268024.html