Question

HI!

I am working with a .json file, like this:

[{  
  "SourceFile": "videos/KobeAlleyOop.flv",  
  "ExifTool": {  
    "ExifToolVersion": 8.22,  
    "Warning": "Truncated 'mdat' data"  
  },  
  "System": {  
    "FileName": "KobeAlleyOop.flv",  
    "Directory": "videos",  
    "FileSize": "4.8 MB",  
    "FileModifyDate": "2010:06:15 14:57:24+02:00",  
    "FilePermissions": "rwxr-xr-x"  
  },  
  "File": {  
    "FileType": "MP4",  
    "MIMEType": "video/mp4"  
  }]  

I made a Bean with 3 components:

 public class MetadataContentBean {   
 SourceFileBean sourceFileBean;  
     FileBean fileBean;    
     SystemBean systemBean;   

     public FileBean getFileBean() {   return fileBean;  }   
 @JsonProperty("File")    
public void setFileBean(FileBean fileBean) {    
 this.fileBean = fileBean;    }   
 public SystemBean getSystemBean() {   
 return systemBean;    }   
 @JsonProperty("System")    
public void setSystemBean(SystemBean systemBean) {
 this.systemBean = systemBean;    }   
 public SourceFileBean
 getSourceFileBean() {    
 sourceFileBean.getSource();     return
 sourceFileBean;    }     
 @JsonProperty("SourceFile")    
public void setSourceFileBean(SourceFileBean
 sourceFileBean) {    
 this.sourceFileBean = sourceFileBean; 
 }   }

And I add an example of SourceFileBean, the others are similar:

public class SourceFileBean {

 private String source;
 public String getSource() {
  return source;
 }
 @JsonProperty("SourceFile")
 public void setSource(String source) {
  this.source = source;
 }
}

In the main program I make this call:

InputStream is = this.getClass().getClassLoader().getResourceAsStream(filename);  
    String jsonTxt = IOUtils.toString(is);  
    JSONArray json = (JSONArray) JSONSerializer.toJSON(jsonTxt);  
    JSONObject metadatacontent = json.getJSONObject(0);  
    ObjectMapper mapper = new ObjectMapper();  mapper.readValue(metadatacontent.toString(),MetadataContentBean.class);

But I get this error when I run it, I don’t know why:

org.codehaus.jackson.map.JsonMappingException:
Can not construct instance of
com.path.bean.SourceFileBean,
problem: no suitable creator method
found at [Source:
java.io.StringReader@12d7a10; line: 1,
column: 2] at
org.codehaus.jackson.map.JsonMappingException.from(JsonMappingException.java:159)
at
org.codehaus.jackson.map.deser.StdDeserializationContext.instantiationException(StdDeserializationContext.java:212)
at
org.codehaus.jackson.map.deser.BeanDeserializer.deserializeFromString(BeanDeserializer.java:415)
at
org.codehaus.jackson.map.deser.BeanDeserializer.deserialize(BeanDeserializer.java:291)
at
org.codehaus.jackson.map.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:135)
at
org.codehaus.jackson.map.deser.SettableBeanProperty$MethodProperty.deserializeAndSet(SettableBeanProperty.java:221)
at
org.codehaus.jackson.map.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:390)
at
org.codehaus.jackson.map.deser.BeanDeserializer.deserialize(BeanDeserializer.java:286)
at
org.codehaus.jackson.map.ObjectMapper._readMapAndClose(ObjectMapper.java:1588)
at
org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1116)
at
com.path.parser.JSon.Parser(JSon.java:65)
at
com.path.parser.JSon.main(JSon.java:29)

Any help?? Thanks in advance!

Answer 1

The problem was about sintaxis and the way of writting the fields in my program.
You must be absotuely sure that it is the SAME as in the json file.

On the other hand

“SourceFile”: “videos/KobeAlleyOop.flv”

is a field with just one field, so is not neccesary make a bean for it.

It is a stupid error which could make you waist a lot of time!!! :s