Java_10 List<Map<String,Object>>遍历

List>遍历

public class Test {
    public static void main(String[] args) {

        List> listMaps = new ArrayList>();
        
        Map map1 = new HashMap();
        map1.put("1", "a");
        map1.put("2", "b");
        map1.put("3", "c");
        listMaps.add(map1);

        Map map2 = new HashMap();
        map2.put("11", "aa");
        map2.put("22", "bb");
        map2.put("33", "cc");
        listMaps.add(map2);

        for (Map map : listMaps) {
            for (String s : map.keySet()) {
                //一般用这个遍历，map.get("key")获取val
                System.out.print(map.get(s) + "  ");
            }
        }
        System.out.println();
        System.out.println("========================");
        for (int i = 0; i < listMaps.size(); i++) {
            Map map = listMaps.get(i);
            Iterator iterator = map.keySet().iterator();
            while (iterator.hasNext()) {
                String string = (String) iterator.next();
                System.out.println(map.get(string));
            }
        }
        System.out.println("++++++++++++++++++++++++++++");
        for (Map map : listMaps) {
            for (Map.Entry m : map.entrySet()) {
                System.out.print(m.getKey() + "    ");
                System.out.println(m.getValue());
            }
        }
        System.out.println("-----------------------------");
    }

}


打印的结果：

c  b  a  bb  cc  aa  
========================
c
b
a
bb
cc
aa
++++++++++++++++++++++++++++
   c
   b
   a
   bb
   cc
   aa
-----------------------------

// 删除list指定元素
 List> products =  null;
         
     //获取List元素
     products = productService.getProduct(); 
     
     //使用迭代删除
     Iterator> productsIterator = products.iterator();   
	 //hasNext判断是否有元素，next获取元素，“pro01”为键的val
     while (productsIterator.hasNext()) { 
       //删除特定元素
       Map product = productsIterator.next();
       
       if("product01".equals(product.get("productName"))){
              productsIterator.remove();
       } 
       if("product02".equals(product.get("productName"))){
            productsIterator.remove();
       }              
    }