java實現具有相同屬性名稱及相似型別的pojo、dto、vo等的互轉
阿新 • • 發佈：2019-01-22
已應用於實際專案：1.thrift物件與dto之間的互轉
2.pojo與dto之間的互轉
3.pojo與vo之間的互轉
1.核心轉換工具類，對特別複雜型別不做處理，因為業務場景還未覆蓋
package littlehow.convert; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.lang.reflect.Field; import java.lang.reflect.Method;import java.lang.reflect.ParameterizedType; import java.lang.reflect.Type; import java.math.BigDecimal; import java.sql.Timestamp; import java.util.*; import java.util.concurrent.ConcurrentHashMap; /** * PojoConvertUtil * * @author littlehow * @time 2017-05-03 16:54 */ public class PojoConvertUtil { private staticLogger logger = LoggerFactory.getLogger(PojoConvertUtil.class); /** * 變數快取 */ private static final Map<String, Map<String, Field>> cacheFields = new ConcurrentHashMap<>(); private static final Set<Class> basicClass = new HashSet<>(); static { basicClass.add(Integer.class); basicClass.add(Character.class); basicClass.add(Byte.class); basicClass.add(Float.class); basicClass.add(Double.class); basicClass.add(Boolean.class); basicClass.add(Long.class); basicClass.add(Short.class); basicClass.add(String.class); basicClass.add(BigDecimal.class); } /** * 將具有相同屬性的型別進行轉換 * @param orig * @param <T> * @return */ public static <T> T convertPojo(Object orig, Class<T> targetClass) { try { T target = targetClass.newInstance(); /** 獲取源物件的所有變數 */ Field[] fields = orig.getClass().getDeclaredFields(); for (Field field : fields) { if (isStatic(field)) continue; /** 獲取目標方法 */ Field targetField = getTargetField(targetClass, field.getName()); if (targetField == null) continue; Object value = getFiledValue(field, orig); if (value == null) continue; Class type1 = field.getType(); Class type2 = targetField.getType(); //兩個型別是否相同 boolean sameType = type1.equals(type2); if (isBasicType(type1)) { if (sameType) setFieldValue(targetField, target, value); } else if (value instanceof Map && Map.class.isAssignableFrom(type2)){//對map setMap((Map)value, field, targetField, target); } else if (value instanceof Set && Set.class.isAssignableFrom(type2)) {//對set setCollection((Collection)value, field, targetField, target); } else if (value instanceof List && List.class.isAssignableFrom(type2)) {//對list setCollection((Collection)value, field, targetField, target); } else if (value instanceof Enum && Enum.class.isAssignableFrom(type2)) {//對enum setEnum((Enum)value, field, targetField, target); } else if (value instanceof java.util.Date && java.util.Date.class.isAssignableFrom(type2)) {//對日期型別，不處理如joda包之類的擴充套件時間，不處理calendar setDate((Date)value, targetField, type2, target, sameType); } } return target; } catch (Throwable t) { logger.error("轉換失敗:" + t.getMessage()); throw new RuntimeException(t.getMessage()); } } /** * 獲取欄位值 * @param field * @param obj * @return */ private static Object getFiledValue(Field field, Object obj) throws IllegalAccessException { //獲取原有的訪問許可權 boolean access = field.isAccessible(); try { //設定可訪問的許可權 field.setAccessible(true); return field.get(obj); } finally { //恢復訪問許可權 field.setAccessible(access); } } /** * 設定方法值 * @param field * @param obj * @param value * @throws IllegalAccessException */ private static void setFieldValue(Field field, Object obj, Object value) throws IllegalAccessException { //獲取原有的訪問許可權 boolean access = field.isAccessible(); try { //設定可訪問的許可權 field.setAccessible(true); field.set(obj, value); } finally { //恢復訪問許可權 field.setAccessible(access); } } /** * 轉換list * @param orig * @param targetClass * @param <T> * @return */ public static <T> List<T> convertPojos(List orig, Class<T> targetClass) { List<T> list = new ArrayList<>(orig.size()); for (Object object : orig) { list.add(convertPojo(object, targetClass)); } return list; } /** * 設定Map * @param value * @param origField * @param targetField * @param targetObject * @param <T> */ private static <T> void setMap(Map value, Field origField, Field targetField, T targetObject) throws IllegalAccessException, InstantiationException{ Type origType = origField.getGenericType(); Type targetType = targetField.getGenericType(); if (origType instanceof ParameterizedType && targetType instanceof ParameterizedType) {//泛型型別 ParameterizedType origParameterizedType = (ParameterizedType)origType; Type[] origTypes = origParameterizedType.getActualTypeArguments(); ParameterizedType targetParameterizedType = (ParameterizedType)targetType; Type[] targetTypes = targetParameterizedType.getActualTypeArguments(); if (origTypes != null && origTypes.length == 2 && targetTypes != null && targetTypes.length == 2) {//正常泛型,檢視第二個泛型是否不為基本型別 Class clazz = (Class)origTypes[1]; if (!isBasicType(clazz) && !clazz.equals(targetTypes[1])) {//如果不是基本型別並且泛型不一致，則需要繼續轉換 Set<Map.Entry> entries = value.entrySet(); Map targetMap = value.getClass().newInstance(); for (Map.Entry entry : entries) { targetMap.put(entry.getKey(), convertPojo(entry.getValue(), (Class) targetTypes[1])); } setFieldValue(targetField, targetObject, targetMap); return; } } } setFieldValue(targetField, targetObject, value); } /** * 設定集合 * @param value * @param origField * @param targetField * @param targetObject * @param <T> * @throws IllegalAccessException * @throws InstantiationException */ private static <T> void setCollection(Collection value, Field origField, Field targetField, T targetObject) throws IllegalAccessException, InstantiationException{ Type origType = origField.getGenericType(); Type targetType = targetField.getGenericType(); if (origType instanceof ParameterizedType && targetType instanceof ParameterizedType) {//泛型型別 ParameterizedType origParameterizedType = (ParameterizedType)origType; Type[] origTypes = origParameterizedType.getActualTypeArguments(); ParameterizedType targetParameterizedType = (ParameterizedType)targetType; Type[] targetTypes = targetParameterizedType.getActualTypeArguments(); if (origTypes != null && origTypes.length == 1 && targetTypes != null && targetTypes.length == 1) {//正常泛型,檢視第二個泛型是否不為基本型別 Class clazz = (Class)origTypes[0]; if (!isBasicType(clazz) && !clazz.equals(targetTypes[0])) {//如果不是基本型別並且泛型不一致，則需要繼續轉換 Collection collection = value.getClass().newInstance(); for (Object obj : value) { collection.add(convertPojo(obj, (Class) targetTypes[0])); } setFieldValue(targetField, targetObject, collection); return; } } } setFieldValue(targetField, targetObject, value); } /** * 設定列舉型別 * @param value * @param origField * @param targetField * @param targetObject * @param <T> */ private static <T> void setEnum(Enum value, Field origField, Field targetField, T targetObject) throws Exception{ if (origField.equals(targetField)) { setFieldValue(targetField, targetObject, value); } else { //列舉型別都具有一個static修飾的valueOf方法 Method method = targetField.getType().getMethod("valueOf", String.class); setFieldValue(targetField, targetObject, method.invoke(null, value.toString())); } } /** * 設定日期型別 * @param value * @param targetField * @param targetFieldType * @param targetObject * @param <T> */ private static <T> void setDate(Date value, Field targetField, Class targetFieldType, T targetObject, boolean sameType) throws IllegalAccessException { Date date = null; if (sameType) { date = value; } else if (targetFieldType.equals(java.sql.Date.class)) { date = new java.sql.Date(value.getTime()); } else if (targetFieldType.equals(java.util.Date.class)) { date = new Date(value.getTime()); } else if (targetFieldType.equals(java.sql.Timestamp.class)) { date = new java.sql.Timestamp(value.getTime()); } setFieldValue(targetField, targetObject, date); } /** * 獲取適配方法 * @param clazz * @param fieldName * @return */ public static Field getTargetField(Class clazz, String fieldName) { String classKey = clazz.getName(); Map<String, Field> fieldMap = cacheFields.get(classKey); if (fieldMap == null) { fieldMap = new HashMap<>(); Field[] fields = clazz.getDeclaredFields(); for (Field field : fields) { if (isStatic(field)) continue; fieldMap.put(field.getName(), field); } cacheFields.put(classKey, fieldMap); } return fieldMap.get(fieldName); } /** * 確實是否為基礎型別 * @param clazz * @return */ public static boolean isBasicType(Class clazz) { return clazz.isPrimitive() || basicClass.contains(clazz); } /** * 判斷變數是否有靜態修飾符static * @param field * @return */ public static boolean isStatic(Field field) { return (8 & field.getModifiers()) == 8; } }
下面這個類是便於輸出展示的，因為只是用於列印，所以不做效率考慮
package littlehow.convert; import java.lang.reflect.Field; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Date; /** * SimpleToStringParent * * @author littlehow * @time 2017-05-04 10:40 */ public class SimpleToStringParent { @Override public String toString() { try { StringBuilder stringBuilder = new StringBuilder("{"); Field[] fields = this.getClass().getDeclaredFields(); DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); for (Field field : fields) { Object value = getFiledValue(field, this); if (value == null) continue; if (value instanceof Date) { //這裡也可以直接轉為時間戳 value = dateFormat.format((Date)value); } stringBuilder.append(field.getName()).append("=").append(value).append(","); } String returnValue = stringBuilder.toString(); if (returnValue.length() > 1) { returnValue = returnValue.substring(0, returnValue.length() - 1); } return this.getClass().getSimpleName() + returnValue + "}"; } catch (Exception e) { // skip } return this.getClass().getSimpleName() + "{}"; } /** * 獲取屬性值 * @param field * @param obj * @return * @throws IllegalAccessException */ private Object getFiledValue(Field field, Object obj) throws IllegalAccessException { //獲取原有的訪問許可權 boolean access = field.isAccessible(); try { //設定可訪問的許可權 field.setAccessible(true); return field.get(obj); } finally { //恢復訪問許可權 field.setAccessible(access); } } }
測試用的4個pojo
1.產品類
package littlehow.convert.pojo; import littlehow.convert.SimpleToStringParent; import java.util.List; /** * Product * * @author littlehow * @time 2017-05-04 09:15 */ public class Product extends SimpleToStringParent { private Integer productId; private String generalName; private String factoryName; private String unit; private String specification; private Integer category; private List<Item> items; public Integer getProductId() { return productId; } public void setProductId(Integer productId) { this.productId = productId; } public String getGeneralName() { return generalName; } public void setGeneralName(String generalName) { this.generalName = generalName; } public String getFactoryName() { return factoryName; } public void setFactoryName(String factoryName) { this.factoryName = factoryName; } public String getUnit() { return unit; } public void setUnit(String unit) { this.unit = unit; } public String getSpecification() { return specification; } public void setSpecification(String specification) { this.specification = specification; } public List<Item> getItems() { return items; } public void setItems(List<Item> items) { this.items = items; } public Integer getCategory() { return category; } public void setCategory(Integer category) { this.category = category; } }
2.商品類
package littlehow.convert.pojo; import littlehow.convert.SimpleToStringParent; import java.util.Date; import java.util.List; /** * Item * * @author littlehow * @time 2017-05-04 09:15 */ public class Item extends SimpleToStringParent { private Long itemId; private String itemName; private Byte status; private Boolean deleted; private Date createTime; private List<Sku> skus; public Long getItemId() { return itemId; } public void setItemId(Long itemId) { this.itemId = itemId; } public String getItemName() { return itemName; } public void setItemName(String itemName) { this.itemName = itemName; } public Byte getStatus() { return status; } public void setStatus(Byte status) { this.status = status; } public Boolean getDeleted() { return deleted; } public void setDeleted(Boolean deleted) { this.deleted = deleted; } public Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } public List<Sku> getSkus() { return skus; } public void setSkus(List<Sku> skus) { this.skus = skus; } }
3.最小庫存單位sku
package littlehow.convert.pojo; import littlehow.convert.SimpleToStringParent; import java.lang.reflect.Field; /** * Sku * * @author littlehow * @time 2017-05-04 09:15 */ public class Sku extends SimpleToStringParent { private Long skuId; private Byte status; private Boolean deleted; private Double price; private Double promoPrice; private Integer inventory; private Integer minBuy; private Integer blockInventory; private Color skuColor; public Long getSkuId() { return skuId; } public void setSkuId(Long skuId) { this.skuId = skuId; } public Byte getStatus() { return status; } public void setStatus(Byte status) { this.status = status; } public Boolean getDeleted() { return deleted; } public void setDeleted(Boolean deleted) { this.deleted = deleted; } public Double getPrice() { return price; } public void setPrice(Double price) { this.price = price; } public Double getPromoPrice() { return promoPrice; } public void setPromoPrice(Double promoPrice) { this.promoPrice = promoPrice; } public Integer getInventory() { return inventory; } public void setInventory(Integer inventory) { this.inventory = inventory; } public Integer getMinBuy() { return minBuy; } public void setMinBuy(Integer minBuy) { this.minBuy = minBuy; } public Integer getBlockInventory() { return blockInventory; } public void setBlockInventory(Integer blockInventory) { this.blockInventory = blockInventory; } public Color getSkuColor() { return skuColor; } public void setSkuColor(Color skuColor) { this.skuColor = skuColor; } }
4.屬性列舉
package littlehow.convert.pojo; /** * Color * * @author littlehow * @time 2017-05-04 09:21 */ public enum Color { BLACK(1), RED(2), BLUE(3), GREEN(4); public final int value; Color(int value) { this.value = value; } public static Color valueOf(int value) { switch (value) { case 1 : return BLACK; case 2 : return RED; case 3 : return BLUE; case 4 : return GREEN; default : throw new IllegalArgumentException(value + " is not a enum value"); } } }
轉換用的dto，當然也可以將dto作為轉換源
1.產品dto
package littlehow.convert.dto; import littlehow.convert.SimpleToStringParent; import littlehow.convert.pojo.Item; import java.util.List; /** * ProductDto * * @author littlehow * @time 2017-05-04 09:16 */ public class ProductDto extends SimpleToStringParent { private Integer productId; private String generalName; private String factoryName; private String unit