详解json string转换为java bean及实例代码

<dependency>
  <groupId>org.codehaus.jackson </groupId>
  <artifactId>jackson-core-asl</artifactId>
  <version>1.9.2</version>
  <scope>provided</scope>
</dependency>

<dependency>
  <groupId>com.alibaba </groupId>
  <artifactId>fastjson</artifactId>
  <version>1.2.7</version>
  <scope>provided</scope>
</dependency>

package test.fastjson;

import java.util.HashMap;
import java.util.Map;

import org.codehaus.jackson.annotate.JsonIgnoreProperties;
import org.codehaus.jackson.annotate.JsonProperty;

//简单地忽略掉从JSON（由于在应用中没有完全匹配的POJO）中获得的所有“多余的”属性
@JsonIgnoreProperties(ignoreUnknown = true)
public class ESMetaDataInfoIndex  
{
  //改变某个成员属性所使用的JSON名称
  @JsonProperty("tableStrategy")
  private String tableStrategy = null;
  @JsonProperty("indexName")
  private String indexName = null;
  @JsonProperty("topic")
  private String topic = null;
  @JsonProperty("nameSpace")
  private String nameSpace = null;
  @JsonProperty("extendAttr")
  private Map<String, String> extendAttr = new HashMap<String, String>();
  @JsonProperty("type")
  private String type = null;
  @JsonProperty("ttl")
  private int ttl = 0;
  @JsonProperty("splitCol")
  private String splitCol = null;


  /**
  **/
  public String getTableStrategy() 
  {
    return tableStrategy;
  }
  public void setTableStrategy(String tableStrategy) 
  {
    this.tableStrategy = tableStrategy;
  }

  /**
  **/
  public String getIndexName() 
  {
    return indexName;
  }
  public void setIndexName(String indexName) 
  {
    this.indexName = indexName;
  }

  /**
  **/
  public String getTopic() 
  {
    return topic;
  }
  public void setTopic(String topic) 
  {
    this.topic = topic;
  }

  /**
  **/
  public String getNameSpace() 
  {
    return nameSpace;
  }
  public void setNameSpace(String nameSpace) 
  {
    this.nameSpace = nameSpace;
  }

  /**
  **/
  public Map<String, String> getExtendAttr() 
  {
    return extendAttr;
  }
  public void setExtendAttr(Map<String, String> extendAttr) 
  {
    this.extendAttr = extendAttr;
  }

  /**
  **/
  public String getType() 
  {
    return type;
  }
  public void setType(String type) 
  {
    this.type = type;
  }

  /**
  **/
  public int getTtl() 
  {
    return ttl;
  }
  public void setTtl(int ttl) 
  {
    this.ttl = ttl;
  }

  /**
  **/
  public String getSplitCol() 
  {
    return splitCol;
  }
  public void setSplitCol(String splitCol) 
  {
    this.splitCol = splitCol;
  }   
}

ESMetaDataInfoIndex dataInfo = JSON.parseObject(json.toJSONString(),ESMetaDataInfoIndex .class);