应用1：将一个bean对象转换为xml格式以字符串形式输出
测试TestBean源码：
public class TestBean {
private String a;
private int b;
private float c;
private byte d;
private long f;
private Character g;
private short i;
private boolean h;
private ReqReturnBean reqReturnBean;
private List strings;
private List integers;
private List floats;
private List bytes;
private List longs;
private List characters;
private List shorts;
private List booleans;
private List returnBeans;
private Set set;
private Set sets;
public TestBean() {
a = "a";
b = 1;
c = 1;
d = 'a';
f = 1;
g = '2';
i = 1;
h = false;
reqReturnBean = new ReqReturnBean();
reqReturnBean.setReferenceNo("1234");
reqReturnBean.setAmount("12");
reqReturnBean.setDevSN("123456");
strings = new ArrayList<>();
strings.add("string1");
strings.add("string2");
strings.add("string3");
strings.add("string4");
integers = new ArrayList<>(Arrays.asList(1, 2));
floats = new ArrayList<>(Arrays.asList(Float.valueOf(1), Float.valueOf(2)));
bytes = new ArrayList<>(Arrays.asList(d, d));
characters = new ArrayList<>(Arrays.asList('a', 'b'));
longs = new ArrayList<>(Arrays.asList(Long.valueOf(1), Long.valueOf(2)));
shorts = new ArrayList<>(Arrays.asList(Short.MAX_VALUE, Short.MIN_VALUE));
booleans = new ArrayList<>(Arrays.asList(false, true));
returnBeans = new ArrayList<>(Arrays.asList(reqReturnBean, reqReturnBean));
set = new HashSet<>();
set.add("dd");
set.add("fff");
sets = new HashSet<>();
sets.add(reqReturnBean);
}
}
bean转xml 源码如下：
public class ReflectUtils {
/** 当前xml标签所处层级数 */
private static int curLayerNum = 0;
/**
* bean 转 xml
* @param bean 待转的bean对象
* @return String xml格式的字符串形式
*/
public static String beanToXml(Object bean) throws IllegalArgumentException, IllegalAccessException {
String root = bean.getClass().getSimpleName();
System.out.println("bean的名字：" + root);
// 进入bean的根标签，当前标签层级数加1
curLayerNum++;
StringBuffer stringBuffer = new StringBuffer();
indentAlign(stringBuffer, curLayerNum);
stringBuffer.append("<" + root + ">\n");
List fieldList = ReflectUtils.getFileds(bean);
if (!fieldList.isEmpty()) {
// 进入bean的子标签，当前标签层级数加1
curLayerNum++;
for (Field field : fieldList) {
field.setAccessible(true);
String fieldName = field.getName();
Object value = field.get(bean);
System.out.println("字段的名称：" + fieldName + " 类型：" + field.getType().getName() + " 值：" + value);
if (ReflectUtils.isBaseType(field.getType().getName())) {
// field的类型 是 基本数据 类型
indentAlign(stringBuffer, curLayerNum);
stringBuffer.append("<" + fieldName + ">" + value + "\n");
} else if (field.getType().equals(java.util.List.class)
|| field.getType().equals(java.util.Set.class)) {
// field的类型 是 List 或 Set 类型
indentAlign(stringBuffer, curLayerNum);
if (!((Collection) value).isEmpty()) {
stringBuffer.append("<" + fieldName + ">\n");
handleCollectionType((Collection) value, stringBuffer);
indentAlign(stringBuffer, curLayerNum);
stringBuffer.append("\n");
} else {
stringBuffer.append("<" + fieldName + ">\n");
}
} else {
/*
* field的类型 是bean对象 类型 因进入bean的根标签curLayerNum会自加1，导致当前标签层级数比实际标签层级数大1，
* 需要将curLayerNum自减1，符合实际情况
*/
curLayerNum--;
stringBuffer.append(beanToXml(value));
}
}
}
// 退出bean的子标签，当前标签层级数减1，返回到bean的根标签
curLayerNum--;
indentAlign(stringBuffer, curLayerNum);
if(curLayerNum == 1) {
// 是转化bean的根标签，则结束标签不需要换行
stringBuffer.append("");
}else {
stringBuffer.append("\n");
}
return stringBuffer.toString();
}
/**
* 以文本的形式保存bean转xml的数据
* @param xmlString 转化的xml字符串
* @param destName 保存文本的位置，例如：C:/Users/Administrator/Desktop/BeanToXml.txt
* @return true：保存成功 ；false：保存失败
*/
public static boolean saveXMLString(String xmlString , String destName) {
FileWriter fileWriter = null;
try {
fileWriter = new FileWriter("C:/Users/Administrator/Desktop/BeanToXml.txt");
fileWriter.write(xmlString);
System.out.println("保存xml文件成功");
return true;
} catch (IOException e) {
e.printStackTrace();
System.out.println("保存xml文件异常");
return false;
} finally {
if(fileWriter != null) {
try {
fileWriter.flush();
fileWriter.close();
System.out.println("正常关闭输出流");
} catch (IOException e) {
e.printStackTrace();
System.out.println("关闭输出流异常");
}
}
}
}
/**
* 获取对象的成员变量
* @param obj
* @return
*/
public static List getFileds(Object obj) {
// 第一步：获取类对象
Class clazz = obj.getClass();
List fieldList = new ArrayList<>();
// 当父类为null的时候说明到达了最上层的父类(Object类)
while (clazz != null && !clazz.getName().toLowerCase().equals("java.lang.object")) {
System.out.println("类对象名字:" + clazz.getName());
fieldList.addAll(Arrays.asList(clazz.getDeclaredFields()));
// 得到父类,然后赋给自己
clazz = clazz.getSuperclass();
}
return fieldList;
}
/**
* 判断object是否为基本类型
* @param typeName
* @return
*/
public static boolean isBaseType(String fieldType) {
switch (fieldType) {
case "java.lang.String":
case "java.lang.Integer":
case "java.lang.Byte":
case "java.lang.Long":
case "java.lang.Float":
case "java.lang.Double":
case "java.lang.Short":
case "java.lang.Boolean":
case "java.lang.Character":
case "int":
case "short":
case "byte":
case "char":
case "long":
case "float":
case "double":
case "boolean":
return true;
default:
return false;
}
}
/** 成员变量类型是集合类型，集合类型转xml格式处理 */
private static void handleCollectionType(Collection obj, StringBuffer xmlString)
throws IllegalArgumentException, IllegalAccessException {
// 进入集合的子标签，当前标签层级数加1
curLayerNum++;
// obj 是 List 或 Set 类型集合
Collection collection = obj;
Iterator iterator = collection.iterator();
while (iterator.hasNext()) {
Object value = iterator.next();
if (isBaseType(value.getClass().getName())) {
indentAlign(xmlString, curLayerNum);
// value是基本数据类型对象
xmlString.append("- " + value + "
\n");
} else {
// value是bean对象，因进入bean的根标签curLayerNum会自加1，导致当前标签层级数比实际标签层级数大1，
// 所以需要将curLayerNum自减1，符合实际情况
curLayerNum--;
xmlString.append(beanToXml(value));
}
}
// 退出集合的子标签，当前标签层级数减1
curLayerNum--;
}
/** xml标签按层级缩进对齐 */
private static void indentAlign(StringBuffer xmlString, int count) {
for (int i = 1; i < count; i++) {
xmlString.append(" ");
}
}