API-en.md

# EasyCommons-EasyObjectUtils

---------------
EasyImageUtils is [EasyCommons](https://github.com/ushelp/EasyCommons "EasyCommons") project group image processing component. 


EasyObjectUtils is EasyCommons project group Obejct operations component. 

## 1. EasyObject FieldExpression language

EasyObjectUtils the tools used to **EasyObject FieldExpression (field expression) language** for property positioning when you operate object.

**Syntax:**
```
Specified attributes: property
Specify the attribute that: property.property
Each object in the specified collection: {collection}
Each object in the specified array: [array] Attribute specifies for each object in the collection: {collection} .property
Attribute specifies for each object in the array: [array] .property

Alias definitions (only for EasyObjectExtract): FieldExpression#Alias
```

## 2. API
EasyObjectUtils It includes the following components:
 
1. **EasyObjectExtract**:Extraction of the object. Using field expression from the object (`FieldExpression`) to extract the specified property deposited **key-value** Map collection.<br/>
 **Scene**: JSON output, specify the output attributes and values extracted from the object.
 ```JAVA
  /**
   * Two ways to modify the properties file (instead of store method):
   * - Merge: The Properties object into the specified file (add, change, delete)
   * - Modify: Modify the Properties object to the specified file (add, change, delete the original file does not include having a parameter)
   *
   *@param object the object data to be extracted
   *@param collection object data set to be extracted
   *@param array array object data to be extracted
   *@param fieldExpressionAndOutNameMap Map list field expression and output alias, optional default field expression name as the output name
   *@param fieldExpressions A list of the fields to be extracted expression, variable parameters, is case-sensitive; support hash character alias definition
   *@return Map collection extracted results
  */
 Map extract(object [, fieldExpressionAndOutNameMap], fieldExpressions)
 List<Map> extract(collection [, fieldExpressionAndOutNameMap], fieldExpressions)
 List<Map> extract(array [, fieldExpressionAndOutNameMap], fieldExpressions)
 ```
 **Example:**
 ```JAVA
 List<Map> list = EasyObjectExtract.extract(getData(), 
 				"userId", "name", "status", "{sysRoles}.name#roleNames",
 				"{sysRoles}.roleId#roleIds");
 ```

2. **EasyObjectFilter**:Object filtering. The JavaBean object properties of special characters (<,>, ...) to filter out, into the escape character; or custom character transformation maps.<br/>
 **Scene** : the special character JavaBean object properties contains a string to filter into character entity; or a character string property objects included replacing all the specified character. For example, the data in the file upload Struts2 package submitted to the object, a special string to the user object may contain submitted escaped.
 ```JAVA
  /**
  * Special character filtering object attribute contains the string, the default Replace <,> is the character entity & lt ;, & gt
   *
   *@param object Object to filter content
   *@param collection set of objects you want to filter content
   *@param array object array to filter content
   *@param specialCharacterMap Filter mapping listparam specialCharacterMap custom (key for the character you want to filter, value character filtered)
   *@param DoNotFieldArray does not filter the array of field names
  */
 filter(object [, specialCharacterMap] [, doNotFieldArray]);
 filter(collection [, specialCharacterMap] [, doNotFieldArray]);
 filter(array [, specialCharacterMap] [, doNotFieldArray]);
 ```
 
  **Example:**
 ```JAVA
 Map replaceMap=new HashMap();
 replaceMap.put("drug","*");
 replaceMap.put("fuck","F***");
 EasyObjectExtract.filter(news,replaceMap);
 ```
 
3. **EasyObjectSetNull**:Object Properties empty. Using field expressions (`FieldExpression`) specified property set to null object.<br/>
   **Scene** : Hibernate object loaded some delay attribute set can not be loaded is empty, to prevent abnormal when no session serialized property.
 ```JAVA
  /**
  * The field is set to the value specified for the null FieldExpression
  *
  *@param Object setNUll of the object to be over
  *@param Collection of objects you want to lead a collection of objects setNUll
  *@param Array array object to object to lead setNUll
  * Expression array list fieldExpressions segmentparam, uncertain parameters
 */
 setNull(Object, fieldExpressions)
 setNull(Collection, fieldExpressions)
 setNull(Object[], fieldExpressions)
 ```
  **Example:**
 ```JAVA
 EasyObjectSetNull.setNull(users, "password","{roles}.rights");
 ```

## 3. Maven
```XML
<!-- EasyObjectUtils -->
<dependency>
	<groupId>cn.easyproject</groupId>
	<artifactId>easycommons-object</artifactId>
	<version>1.7.4-RELEASE</version>
</dependency>
```


## End

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