通过map自动获取url参数值

谁践踏了优雅 2022-06-07 12:29 243阅读 0赞

从页面传递参数到后台，不管是form表单提交还是ajax请求或者是url问号传参，都可以通过构建实体类自动获取到参数的名称和它所对应的数值，只需要一个实体类和一个方法

PageData的实体类

import java.util.Collection;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Set;
    
    import javax.servlet.http.HttpServletRequest;
    public class PageData extends HashMap implements Map{
    	
    	private static final long serialVersionUID = 1L;
    	
    	Map map = null;
    	HttpServletRequest request;
    	
    	public PageData(HttpServletRequest request){
    		this.request = request;
    		Map properties = request.getParameterMap();
    		Map returnMap = new HashMap(); 
    		Iterator entries = properties.entrySet().iterator(); 
    		Map.Entry entry; 
    		String name = "";  
    		String value = "";  
    		while (entries.hasNext()) {
    			entry = (Map.Entry) entries.next(); 
    			name = (String) entry.getKey(); 
    			Object valueObj = entry.getValue(); 
    			if(null == valueObj){ 
    				value = ""; 
    			}else if(valueObj instanceof String[]){ 
    				String[] values = (String[])valueObj;
    				for(int i=0;i<values.length;i++){ 
    					 value = values[i] + ",";
    				}
    				value = value.substring(0, value.length()-1); 
    			}else{
    				value = valueObj.toString(); 
    			}
    			returnMap.put(name, value); 
    		}
    		map = returnMap;
    	}
    	
    	public PageData() {
    		map = new HashMap();
    	}
    	
    	@Override
    	public Object get(Object key) {
    		Object obj = null;
    		if(map.get(key) instanceof Object[]) {
    			Object[] arr = (Object[])map.get(key);
    			obj = request == null ? arr:(request.getParameter((String)key) == null ? arr:arr[0]);
    		} else {
    			obj = map.get(key);
    		}
    		return obj;
    	}
    	
    	public String getString(Object key) {
    		return (String)get(key);
    	}
    	
    	@SuppressWarnings("unchecked")
    	@Override
    	public Object put(Object key, Object value) {
    		return map.put(key, value);
    	}
    	
    	@Override
    	public Object remove(Object key) {
    		return map.remove(key);
    	}
    
    	public void clear() {
    		map.clear();
    	}
    
    	public boolean containsKey(Object key) {
    		// TODO Auto-generated method stub
    		return map.containsKey(key);
    	}
    
    	public boolean containsValue(Object value) {
    		// TODO Auto-generated method stub
    		return map.containsValue(value);
    	}
    
    	public Set entrySet() {
    		// TODO Auto-generated method stub
    		return map.entrySet();
    	}
    
    	public boolean isEmpty() {
    		// TODO Auto-generated method stub
    		return map.isEmpty();
    	}
    
    	public Set keySet() {
    		// TODO Auto-generated method stub
    		return map.keySet();
    	}
    
    	@SuppressWarnings("unchecked")
    	public void putAll(Map t) {
    		// TODO Auto-generated method stub
    		map.putAll(t);
    	}
    
    	public int size() {
    		// TODO Auto-generated method stub
    		return map.size();
    	}
    
    	public Collection values() {
    		// TODO Auto-generated method stub
    		return map.values();
    	}
    	
    }

BaseController中的方法

/**
     * BaseController
     */
    public class BaseController {
    	
    	private final static String SUCCESS = "1";//成功
    	private final static String ERROR = "0";//异常
    	
    	/**
    	 * 返回正确结果
    	 * @param msg 文本内容
    	 * @param data 返回数据对象
    	 * @return
    	 */
    	public ReturnMap success(String msg, Object data){
    		return new ReturnMap()
    				.state(SUCCESS)
    				.msg(msg)
    				.data(data);
    	}
    	
    	/**
    	 * 返回正确结果
    	 * @param state
    	 * @param msg
    	 * @return
    	 */
    	public ReturnMap success(String msg){
    		return success(msg, null);
    	}
    	
    	/**
    	 * 返回错误结果
    	 * @param state
    	 * @param msg
    	 * @return
    	 */
    	public ReturnMap fail(String msg){
    		return new ReturnMap()
    				.state(ERROR)
    				.msg(msg);
    	}
    	
    	
    	/**
    	 * 得到PageData
    	 */
    	public PageData getPageData(){
    		return new PageData(this.getRequest());
    	}
    	
    	/**
    	 * 得到ModelAndView
    	 */
    	public ModelAndView getModelAndView(){
    		return new ModelAndView();
    	}
    	
    	/**
    	 * 得到request对象
    	 */
    	public HttpServletRequest getRequest() {
    		HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();
    		
    		return request;
    	}
    
    	/**
    	 * 得到32位的uuid
    	 * @return
    	 */
    	public String get32UUID(){
    		
    		return UuidUtil.get32UUID();
    	}
    }

在controller中继承这个基础的类，调用其中的方法即可

![20171021145542648][]

这样在PageData的对象中，自动获取到了所有的参数名称和它对应的数值

[20171021145542648]: /images/20220607/61271e926e694c8da6e2096de7c5c398.png