com.ibm.portal.streaming.json
Interface JsonContentHandler

All Known Subinterfaces:

DefaultJsonContentHandler, JsonContentHandlerEx, JsonDocumentContentHandler

public interface JsonContentHandler

Content handler that defines events for JSON data structures. This interface can be used to both generate and parse JSON data. It is modelled after the ContentHandler interface. For JSON generation is it more convenient to use the DefaultJsonContentHandler wrapper. For JSON parsing consider to subclass your parser from EmptyJsonContentHandler.

The JSON data is represented as a stream of events. The events begin with startDocument() and end with endDocument(). Each JSON data type is represented by a startXXX event, followed by the content, followed by an endXXX event. For objects and arrays these events may be nested.

String values are represented as callbacks to the value(char[], int, int) method. Depending on the size of the string, there might be multiple calls to represent a single value. String values are always sent in their unescaped format.

Example: The following JSON structure

 {
     "Image": {
         "Height": 600,
         "Width": 800,
         "Title": "View from 15th Floor",
         "Thumbnail": {
             "Height": 125,
             "Url": "http://www.example.com/image/481989943",
             "Width": "100"
         }
     },
     "IDs": [
         116,
         943,
         234,
         38793
     ]
 }
 

is represented via the following events

 startDocument();
 startObject();
 startMember("Image");
 startObject();
 startMember("Width");
 startNumber();
 value(800);
 endNumber();
 endMember();
 startMember("Height");
 startNumber();
 value(600);
 endNumber();
 endMember();
 startMember("Title");
 startString();
 value("View from 15th Floor", .., ..);
 endString();
 endMember();
 startMember("Thumbnail");
 startObject();
 startMember("Url");
 startString();
 value("http://www.example.com/image/481989943", .., ..);
 endString();
 endMember();
 startMember("Height");
 startNumber();
 value(125);
 endNumber();
 endMember();
 startMember("Width");
 startString();
 value("100", .., ..);
 endString();
 endMember();           
 endObject();
 endMember();
 startMember("IDs");
 startArray();
 startNumber();
 value(116);
 endNumber();
 startNumber();
 value(943);
 endNumber();
 startNumber();
 value(234);
 endNumber();
 startNumber();
 value(38793);
 endNumber();
 endArray();
 endMember();           
 endObject();
 endMember();
 endObject();
 endDocument();
 

See Also:

DefaultJsonContentHandler, EmptyJsonContentHandler

Note:

This interface is designed to be implemented by clients.

Method Summary

void	endArray() Indicates the end of an array
void	endBoolean() Indicates the end of a boolean value
void	endDocument() Indicates the end of the event sequence
void	endMember() Indicates the end of a member inside an object
void	endNull() Indicates the end of the null token
void	endNumber() Indicates the end of a numerical value
void	endObject() Indicates the end of an object
void	endString() Indicates the end of a string based value
void	startArray() Indicates the start of an array
void	startBoolean() Indicates the start of a boolean value
void	startDocument() Indicates the start of the event sequence
void	startMember(java.lang.String name) Indicates the start of a member inside an object
void	startNull() Indicates the start of the null token
void	startNumber() Indicates the start of a numerical value, either of integer or floating type
void	startObject() Indicates the start of an object
void	startString() Indicates the start of a string based value
void	value(boolean value) Writes a boolean value
void	value(char[] cbuf, int off, int len) Streams the content of a string value in its unescaped form
void	value(double value) Writes a floating value
void	value(long value) Writes an integer value

Method Detail

endArray

void endArray()
              throws java.io.IOException

Indicates the end of an array

Throws:

java.io.IOException

endBoolean

void endBoolean()
                throws java.io.IOException

Indicates the end of a boolean value

Throws:

java.io.IOException

endDocument

void endDocument()
                 throws java.io.IOException

Indicates the end of the event sequence

Throws:

java.io.IOException

endMember

void endMember()
               throws java.io.IOException

Indicates the end of a member inside an object

Throws:

java.io.IOException

endNull

void endNull()
             throws java.io.IOException

Indicates the end of the null token

Throws:

java.io.IOException

endNumber

void endNumber()
               throws java.io.IOException

Indicates the end of a numerical value

Throws:

java.io.IOException

endObject

void endObject()
               throws java.io.IOException

Indicates the end of an object

Throws:

java.io.IOException

endString

void endString()
               throws java.io.IOException

Indicates the end of a string based value

Throws:

java.io.IOException

startArray

void startArray()
                throws java.io.IOException

Indicates the start of an array

Throws:

java.io.IOException

startBoolean

void startBoolean()
                  throws java.io.IOException

Indicates the start of a boolean value

Throws:

java.io.IOException

startDocument

void startDocument()
                   throws java.io.IOException

Indicates the start of the event sequence

Throws:

java.io.IOException

startMember

void startMember(java.lang.String name)
                 throws java.io.IOException

Indicates the start of a member inside an object

Parameters:

name - name of the member in its unescaped form, not null

Throws:

java.io.IOException

startNull

void startNull()
               throws java.io.IOException

Indicates the start of the null token

Throws:

java.io.IOException

startNumber

void startNumber()
                 throws java.io.IOException

Indicates the start of a numerical value, either of integer or floating type

Throws:

java.io.IOException

startObject

void startObject()
                 throws java.io.IOException

Indicates the start of an object

Throws:

java.io.IOException

startString

void startString()
                 throws java.io.IOException

Indicates the start of a string based value

Throws:

java.io.IOException

value

void value(boolean value)
           throws java.io.IOException

Writes a boolean value

Parameters:

value - the boolean

Throws:

java.io.IOException

value

void value(char[] cbuf,
           int off,
           int len)
           throws java.io.IOException

Streams the content of a string value in its unescaped form

Parameters:

cbuf - character buffer holding the data, not null

off - index of the first valid character in the buffer

len - length of the valid sequence

Throws:

java.io.IOException

value

void value(double value)
           throws java.io.IOException

Writes a floating value

Parameters:

value - the value, not NaN nor Infinity

Throws:

java.io.IOException

value

void value(long value)
           throws java.io.IOException

Writes an integer value

Parameters:

value - the integer

Throws:

java.io.IOException