Jackson处理xml和csv和java对象互转

程序员文章站 2022-05-01 17:43:56

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Jackson处理json,xml,csv

可以方便地实现序列化和反序列化,实现三者互转以及java bean互转

maven依赖

		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-core</artifactId>
			<version>2.6.3</version>
		</dependency>

		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
			<version>2.6.3</version>
		</dependency>

		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-annotations</artifactId>
			<version>2.6.3</version>
		</dependency>

		<dependency>
			<groupId>com.fasterxml.jackson.dataformat</groupId>
			<artifactId>jackson-dataformat-csv</artifactId>
			<version>2.7.3</version>
		</dependency>

		<dependency>
			<groupId>com.fasterxml.jackson.dataformat</groupId>
			<artifactId>jackson-dataformat-xml</artifactId>
			<version>2.7.3</version>
		</dependency>

		<dependency>
			<groupId>org.codehaus.woodstox</groupId>
			<artifactId>woodstox-core-asl</artifactId>
			<version>4.4.1</version>
		</dependency>

Xml工具类

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;

public class XmlUtil {

	private static final Logger logger = LogManager.getLogger(XmlUtil.class);

	private static final XmlMapper xmlMapper = new XmlMapper();

	private XmlUtil() {

	}

	/**
	 * 输出全部属性 如果xml中存在，对象中没有，则自动忽略该属性 失败返回null
	 * 
	 * @param xmlContent
	 * @param clazz
	 * @return
	 */
	public static <T> T toNormalObject(String xmlContent, Class<T> clazz) {
		return xmlToObject(xmlContent, clazz);
	}
	
	/**
	 * 输出全部属性 
	 * 如果xml中存在，对象中没有，则自动忽略该属性 
	 * 失败返回null
	 * @param inputStream
	 * @param clazz
	 * @return
	 */
	public static <T> T toNormalObject(byte[] bytes, Class<T> clazz) {
		return xmlToObject(bytes, clazz);
	}

	/**
	 * 输出全部属性 失败返回""
	 * 
	 * @param object
	 * @return
	 */
	public synchronized static byte[] toNormalXml(Object object) {
		return objectToXml(Include.ALWAYS, object);
	}

	private static <T> T xmlToObject(byte[] bytes, Class<T> clazz) {
		try {
			return xmlMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).readValue(bytes, clazz);
		} catch (Exception e) {
			logger.info("XmlToObject failed:", e);
		}
		return null;
	}
	
	private static <T> T xmlToObject(String xmlContent, Class<T> clazz) {
		try {
			return xmlMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).readValue(xmlContent, clazz);
		} catch (Exception e) {
			logger.info("XmlToObject failed:", e);
		}
		return null;
	}
	
	private static <T> byte[] objectToXml(Include include, T object) {
		try {
			return xmlMapper.setSerializationInclusion(include).writerWithDefaultPrettyPrinter().writeValueAsBytes(object);
		} catch (JsonProcessingException e) {
			logger.info("ObjToXml failed:", e);
		}
		return null;
	}

}

Csv工具类

import java.util.List;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.MappingIterator;
import com.fasterxml.jackson.dataformat.csv.CsvMapper;
import com.fasterxml.jackson.dataformat.csv.CsvSchema;

public class CsvUtil {
	
	private static final Logger logger = LogManager.getLogger(CsvUtil.class);
	
	private static final CsvMapper csvMapper = new CsvMapper();
	
	private CsvUtil(){
		
	}
	
	/**
	 * 输出全部属性 
	 * 如果csv中存在，对象中没有，则自动忽略该属性 
	 * 失败返回null
	 * 
	 * @param csvContent
	 * @param clazz
	 * @return
	 */
	public static <T> List<T> toNormalObject(String csvContent, Class<T> clazz) {
		try {
			CsvSchema schema = CsvSchema.emptySchema().withHeader();
			MappingIterator<T> mappingIterator = csvMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).readerFor(clazz).with(schema).readValues(csvContent);
			return mappingIterator.readAll();
		} catch (Exception e) {
			logger.info("CsvToObject failed:", e);
		}
		return null;
	}
	
	/**
	 * 输出全部属性 
	 * 如果csv中存在，对象中没有，则自动忽略该属性 
	 * 失败返回null
	 * @param inputStream
	 * @param clazz
	 * @return
	 */
	public synchronized static <T> List<T> toNormalObject(byte[] bytes, Class<T> clazz) {
		try {
			CsvSchema schema = CsvSchema.emptySchema().withHeader();
			MappingIterator<T> mappingIterator = csvMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES).readerFor(clazz).with(schema).readValues(bytes);
			return mappingIterator.readAll();
		} catch (Exception e) {
			logger.info("CsvToObject failed:", e);
		}
		return null;
	}

	/**
	 * 输出全部属性 失败返回""
	 * 
	 * @param object
	 * @return
	 */
	public static String toNormalCsv(Object object) {
		return objectToCsv(Include.ALWAYS, object);
	}

	private static <T> String objectToCsv(Include include, T object) {
		try {
			CsvSchema csvSchema = csvMapper.schemaFor(object.getClass());
			return csvMapper.setSerializationInclusion(include).writer(csvSchema).writeValueAsString(object);
		} catch (JsonProcessingException e) {
			logger.info("ObjToCsv failed:", e);
		}
		return "";
	}

}

Json工具类

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonUtil {

	private static final Logger logger = LoggerFactory.getLogger(JsonUtil.class);

	private static ObjectMapper objectMapper = new ObjectMapper();
	
	/**
	 * 输出全部属性
	 * 失败返回""
	 * @param object
	 * @return
	 */
	public static String toNormalJson(Object object) {
		return toJson(Include.ALWAYS, object);
	}

	/**
	 * 输出非空属性
	 * 失败返回""
	 * @param object
	 * @return
	 */
	public static String toNonNullJson(Object object) {
		return toJson(Include.NON_NULL, object);
	}

	/**
	 * 输出非Null且非Empty(如List.isEmpty)的属性
	 * 失败返回""
	 * @param object
	 * @return
	 */
	public static String toNonEmptyJson(Object object) {
		return toJson(Include.NON_EMPTY, object);
	}
	
	/**
	 * 转成Json
	 * @param include
	 * @param object
	 * @return
	 */
	private static String toJson(Include include, Object object) {
		try {
			objectMapper.setSerializationInclusion(include);
			return objectMapper.writeValueAsString(object);
		} catch (Exception e) {
			logger.info("Obj转Json报错：", e);
		}
		return "";
	}
	
	/**
	 * 输出全部属性
	 * 如果json中存在，对象中没有，则自动忽略该属性
	 * 失败返回null
	 * 
	 * @param json
	 * @param clazz
	 * @return
	 */
	public static <T> T toNormalObject(String json, Class<T> clazz) {
		return toObject(json, clazz);
	}
	
	/**
	 * 转成Object
	 * @param include
	 * @param json
	 * @param clazz
	 * @return
	 */
	private static <T> T toObject(String json, Class<T> clazz) {
		try {
			objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
			return objectMapper.readValue(json, clazz);
		} catch (Exception e) {
			logger.info("Json转Obj报错：", e);
		}
		return null;
	}

}

Java bean实体类(get set省略)

csv使用@JsonProperty来注解csv文件的列名

xml使用@JacksonXmlProperty来注解xml的属性

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;

public class CsvItem {

	@JacksonXmlProperty(localName = "Label")
	@JsonProperty("Display Name")
	private String label;

	@JacksonXmlProperty(localName = "ValueType")
	@JsonProperty
	private String valueType;

	@JacksonXmlProperty(localName = "Editable")
	@JsonProperty("Editable")
	private String editable;

	@JacksonXmlProperty(localName = "Required")
	@JsonProperty("Required")
	private String required;

}

import java.util.List;

import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;

@JacksonXmlRootElement(localName = "Page")
public class CsvPage {

	@JacksonXmlElementWrapper(useWrapping = false)
	@JacksonXmlProperty(localName = "Item")
	private List<CsvItem> csvItems;

	public CsvPage() {

	}

	public CsvPage(List<CsvItem> csvItems) {
		this.csvItems = csvItems;
	}

	public List<CsvItem> getCsvItems() {
		return csvItems;
	}

	public void setCsvItems(List<CsvItem> csvItems) {
		this.csvItems = csvItems;
	}

}

注意scv需要设置schema也就是csv文件的列名

public static <T> List<T> toNormalObject(byte[] bytes, Class<T> clazz) throws JsonProcessingException, IOException {
	CsvSchema schema = CsvSchema.emptySchema().withHeader();
	MappingIterator<T> mappingIterator = csvMapper
			.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
			.readerFor(clazz).with(schema).readValues(bytes);
	return mappingIterator.readAll();
}

xml文件如果需要格式化输出

xmlMapper.setSerializationInclusion(include).writerWithDefaultPrettyPrinter().writeValueAsBytes(object);

writerWithDefaultPrettyPrinter需要依赖

<groupId>org.codehaus.woodstox</groupId>
<artifactId>woodstox-core-asl</artifactId>

例子中的xml文件

<Page>
  <Item>
    <Label>Account</Label>
    <ValueType/>
    <Editable>true</Editable>
    <Required>true</Required>
  </Item>
  <Item>
    <Label>Outstanding</Label>
    <ValueType/>
    <Editable>false</Editable>
    <Required>false</Required>
  </Item>
</Page>

例子中的csv文件

Display Name,Editable,Required
Account,TRUE,TRUE
Outstanding,FALSE,FALSE

例子中csv文件有三个属性xml有四个属性,所以xml中<ValueType/>属性为空

由于Jackson处理Json内容比较多

下一篇有时间再详细说明

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