一种公认的toString()方法

package com.heima.toString;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.ArrayList;

public class ObjectAnalyzer {
	private ArrayList<Object> visited = new ArrayList<Object>();

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		ArrayList<Integer> squaresArrayList = new ArrayList<Integer>();
		for (int i = 1; i <= 5; i++) {
			squaresArrayList.add(i * i);
		}
		System.out.println(new ObjectAnalyzer().toString(squaresArrayList));
	}

	public String toString(Object obj) {
		if (obj == null) {
			return "null";
		}
		if (visited.contains(obj)) {
			return "...";
		}
		visited.add(obj);
		Class cl = obj.getClass();
		if (cl == String.class) {
			return (String) obj;
		}
		if (cl.isArray()) {
			String r = cl.getComponentType() + "[]{";
			for (int i = 0; i < Array.getLength(obj); i++) {
				if (i > 0) {
					r += ",";
				}
				Object val = Array.get(obj, i);
				if (cl.getComponentType().isPrimitive()) {
					r += val;
				} else {
					r += toString(val);
				}
			}
			return r + "}";
		}
		String r = cl.getName();
		// inspect the fields of this class and all superClass
		do {
			r += "[";
			Field[] fields = cl.getDeclaredFields();
			AccessibleObject.setAccessible(fields, true);
			// get the names and values of all fields
			for (Field f : fields) {
				if (!Modifier.isStatic(f.getModifiers())) {
					if (!r.endsWith("[")) {
						r += ",";
					}
					r += f.getName() + "=";
					try {
						Class t = f.getType();
						Object val = f.get(obj);
						if (t.isPrimitive()) {
							r += val;
						} else {
							r += toString(val);
						}
					} catch (Exception e) {
						// TODO: handle exception
						e.printStackTrace();
					}
				}
			}
			r += "]";
			cl = cl.getSuperclass();
		} while (cl != null);

		return r;
	}

}