import java.util.Map;
import java.util.Properties;
import java.util.Set;/*** properties（map）增.删.改.查.遍历*/
public class Demo1 {public static void main(String[] args) {Properties prop = new Properties();System.out.println("添加：添加一个键值对");prop.put("a", "aaa");prop.put("b", "bbb");prop.put("c", "ccc");prop.put("d", "ddd");System.out.println(prop);System.out.println();System.out.println();System.out.println("删除：根据指定的键删除对应的键值对");prop.remove("a");System.out.println("删除a的键之后：" + prop);System.out.println();System.out.println();System.out.println("改：根据键，去修改对应的值");prop.put("b", "java");System.out.println("修改b的值" + prop);System.out.println();System.out.println();System.out.println("查:根据key 获得value");Object value = prop.get("c");System.out.println("获得键C的值: " + value);System.out.println();System.out.println();System.out.println("获得所有的键，根据键遍历");Set<Object> keySet = prop.keySet();for (Object key : keySet) {Object kevalue = prop.get(key);System.out.println(key + "=======" + kevalue);}System.out.println();System.out.println();System.out.println("获得所有的键值对进行遍历");Set<Map.Entry<Object, Object>> entries = prop.entrySet();for (Map.Entry<Object, Object> entry : entries) {Object ek = entry.getKey();Object ev = entry.getValue();System.out.println(ek + "=====" + ev);}}
}