1.获取java entity里的属性有俩个方法：getDeclaredField()和getField();
getField() 只能获取public类型的属性；
getDeclaredField() 能获取类或接口声明的所有属性；
如：
import java.lang.reflect.*;
public class HellWorld{
private double a;
public static final int b = 16;
String str = "helloword";
public static void main(String args[]) {
try {
Class cls = Class.forName("HellWorld");
Field fieldlist[] = cls.getDeclaredFields();
for (int i = 0; i < fieldlist.length; i++) {
Field fld = fieldlist[i];
System.out.println("name = " + fld.getName()); //获取属性名
System.out.println("decl class = " + fld.getDeclaringClass()); //所属的声明类
System.out.println("type = " + fld.getType()); //获取属性类型
int mod = fld.getModifiers();
System.out.println("modifiers = " + Modifier.toString(mod)); //属性成员的修饰语
System.out.println("///////////////");
}
}
catch (Throwable e) {
System.err.println(e);
}
}
}
输出：
1 name = a 2 decl class = class HellWorld 3 type = double 4 modifiers = private 5 ///////////////// 6 name = b 7 decl class = class HellWorld 8 type = int 9 modifiers = public static final 10 ///////////////// 11 name = str 12 decl class = class HellWorld 13 type = class java.lang.String 14 modifiers = 15 /////////////////
使用场景：可以根据页面post/get过来的参数值，初始化java entity里的对应属性的值。
如：POST a=2&str=test
1 public void init(HttpServletRequest request){ 2 try { 3 String queryBody = IOUtils.toString(request.getInputStream()); 4 5 Class cls = Class.forName("HelloWorld"); 6 7 if(StringUtils.isNotBlank(queryBody)){ 8 StringTokenizer st = new StringTokenizer(queryBody, "&"); 9 10 while (st.hasMoreTokens()) { 11 String pairs = st.nextToken(); 12 String key = pairs.substring(0, pairs.indexOf('=')); 13 String value = pairs.substring(pairs.indexOf('=') + 1); 14 15 if(StringUtils.isBlank(value)) 16 continue; 17 18 value = URLDecoder.decode(value, "UTF-8"); 19 20 Field fld = cls.getDeclaredField(key); 21 Class type = fld.getType(); 22 if(type.toString().equalsIgnoreCase("double")){ 23 fld.setDouble(this, Double.parseDouble(value)); 24 }else{ 25 fld.set(this, value); 26 } 27 } 28 } 29 30 } catch(UnsupportedEncodingException e){
31 } catch (IOException e) {
32 } catch (SecurityException e) {
33 } catch (NoSuchFieldException e) {
34 } catch (ClassNotFoundException e) {
35 } catch (IllegalArgumentException e) {
36 } catch (IllegalAccessException e) {
37 } 38 }