自定义test之java两个对象之间值的异同

    作者在java开发过程中遇到项目迁移——从一个大的系统中把一个模块迁移出来做为一个单独的系统服务（微服务），在迁移过程中会遇到大量的功能相同的java对象vo比较问题（新老系统相似功能的 vo对接——相互替代的对象），毕竟新系统的新vo多少会和老系统的vo做些优化、改进之类的，所以便有了两个类似vo对象值之间的比较，人工比较简直要眼瞎，所以作者简单写了一个小的ava两个对象之间值的异同的比较工具，比较简单，目前只提供了简单类型的比较，map,集合类型的暂时还未实现，后续完成...

//两个对象类型属性和值比较

public static Map<String,Object> compareObjectDiffFieldAndValue(Object fromObject,Object toObject) throws Exception {

Map<String,Object> result = new LinkedHashMap<String, Object>();

Field[] fromFields = fromObject.getClass().getDeclaredFields();

Field[] toFields = toObject.getClass().getDeclaredFields();

if(fromFields == null || toFields == null){

return result;

}

Map<String,String> fromFieldMap = new HashMap<String, String>();

Map<String,String> toFieldMap = new HashMap<String, String>();

Map<String,Field> commonFieldMap = new HashMap<String, Field>();

for(int i=0;i<toFields.length + fromFields.length;i++){

if(i<toFields.length){

toFieldMap.put(toFields[i].getType()+toFields[i].getName(),toFields[i].getName());

}else{

String fromKey = fromFields[i-toFields.length].getType() + fromFields[i-toFields.length].getName();

if(toFieldMap.get(fromKey) != null){

commonFieldMap.put(fromKey,fromFields[i-toFields.length]);

toFieldMap.remove(fromKey);

}else{

fromFieldMap.put(fromKey,fromFields[i-toFields.length].getName());

}

}

}

Map<String,Map<String,Object>> commonFieldUnequalMap = new HashMap<String, Map<String,Object>>();

Map<String,String> commonFieldExceptionMap = new HashMap<String, String>();//调用get方法异常属性列表

Iterator<Map.Entry<String,Field>> iterator = commonFieldMap.entrySet().iterator();

while(iterator.hasNext()) {

Field field = iterator.next().getValue();

Object fromFieldValue = null;

Object toFieldValue = null;

try {

PropertyDescriptor fromProperty = new PropertyDescriptor(field.getName(), fromObject.getClass());

PropertyDescriptor toProperty = new PropertyDescriptor(field.getName(), toObject.getClass());

Method fromReadMethod = fromProperty.getReadMethod();

Method toReadMethod = toProperty.getReadMethod();

fromFieldValue = fromReadMethod.invoke(fromObject);

toFieldValue = toReadMethod.invoke(toObject);

} catch (Exception e) {

System.out.println("Exception:" + e.getClass() + " message:" + e.getMessage());

String commomFieldUnequalKey = field.getType() + field.getName();

iterator.remove();

commonFieldExceptionMap.put(commomFieldUnequalKey, field.getName());

continue;

}

if (fromFieldValue == toFieldValue || (toFieldValue != null && toFieldValue.equals(fromFieldValue))) {

} else if(hasClassObject(fromFieldValue) && hasClassObject(toFieldValue)){

Map<String,Object> temResult = compareObjectDiffFieldAndValue(fromFieldValue,toFieldValue);

List<String> commonFieldUnequalList = (List<String>) temResult.get("commonFieldUnequalList");

if(commonFieldUnequalList != null && commonFieldUnequalList.size() > 0) {

StringBuilder names = new StringBuilder();

names.append("{");

for (Object obj : commonFieldUnequalList) {

// String name = obj.toString().split(" -> ")[0];

names.append(obj.toString()).append(" ,");

}

names = names.deleteCharAt(names.length() - 1);

names.append("}");

String commomFieldUnequalKey = field.getType() + field.getName();

iterator.remove();

Map<String, Object> map = new HashMap<String, Object>();

map.put("fieldName", field.getName());

map.put("isClass", "YES");

map.put("names", names.toString());

commonFieldUnequalMap.put(commomFieldUnequalKey, map);

}

}else{

String commomFieldUnequalKey = field.getType()+field.getName();

iterator.remove();

Map<String,Object> map = new HashMap<String, Object>();

map.put("fieldName",field.getName());

map.put("fieldFromValue",fromFieldValue);

map.put("fieldToValue",toFieldValue);

commonFieldUnequalMap.put(commomFieldUnequalKey,map);

}

}

List<String> fromFieldList = new ArrayList<String>();

List<String> toFieldList = new ArrayList<String>();

List<String> commonFieldList = new ArrayList<String>();

List<String> commonFieldUnequalList = new ArrayList<String>();

List<String> commonFieldExceptionList = new ArrayList<String>();

fromFieldList.addAll(fromFieldMap.values());

toFieldList.addAll(toFieldMap.values());

commonFieldExceptionList.addAll(commonFieldExceptionMap.values());

for(Field field:commonFieldMap.values()){

commonFieldList.add(field.getName());

}

for(Map<String,Object> map:commonFieldUnequalMap.values()){

if(map.get("isClass") != null){

commonFieldUnequalList.add(map.get("fieldName").toString() + " -> " + map.get("names"));

}else {

commonFieldUnequalList.add(map.get("fieldName").toString() + " -> " + map.get("fieldFromValue") + " vs " + map.get("fieldToValue"));

}

}

result.put("fromFieldList",fromFieldList);

result.put("toFieldList",toFieldList);

result.put("commonFieldList",commonFieldList);

result.put("commonFieldUnequalList",commonFieldUnequalList);

result.put("commonFieldExceptionList",commonFieldExceptionList);

return result;

}

private static boolean hasClassObject(Object obj){

if(obj instanceof String || obj instanceof Byte || obj instanceof Character || obj instanceof Integer || obj instanceof Long || obj instanceof Short

|| obj instanceof Boolean || obj instanceof Float || obj instanceof Double || obj instanceof Date || obj instanceof

Map || obj instanceof Collection){//map list暂时不做深入处理

return false;

}

return true;

}

fromFieldList：from对象的独有属性结合，toFieldList：to对象的独有属性集合，commonFieldList：二者共同的属性集合，commonFieldUnequalList：二者属性相同而值不同的集合（列出了属性的两个不同的值内容 ），commonFieldExceptionList：处理过程中异常的属性结合

代码的基本思路是反射先拿到两个对象的属性集合，进一步对两对象的属性名称和类型进行判断，找出名称和类型相同的属性，再利用反射调用属性的get方法获取属性的值，进一步比较值是否相等，如果不等则列出两个不同的值，方便查看。