JSONLimitStreamReader

java.lang.Object
- org.json.stream.JSONStreamReader
- - org.json.stream.JSONLimitStreamReader

public final class JSONLimitStreamReader
extends JSONStreamReader

Reads a JSON document as a stream of JSON events, using secure principles derived from XML parsers. Uses an iterator model to produce each event. Similar to a StAX event model in XML processing.

The JSONLimitStreamReader class is similar to the JSONStreamReader class, but intended to be more robust against untrusted JSON sources. For a more robust solution to building object structures, see JSONLimitBuilder.

A simple example of how to use this class:

 JSONLimitStreamReader reader = new JSONLimitStreamReader(JSON_TEXT);
 reader.withLimits(BuilderLimits.secureDefaults());

 while(reader.hasNext()) {
     ParseState state = reader.nextState();
     switch(state) {
         case KEY:
             System.out.println("KEY = " + reader.nextKey() );
             break;
         case NULL_VALUE:
         case BOOLEAN_VALUE:
         case NUMBER_VALUE:
         case STRING_VALUE:
             System.out.println(state + " = " + reader.nextValue());
             break;
         default:
             System.out.println(state);
     }
 }

For a streaming equivalent for writing JSON data, see the JSONWriter and JSONStringer classes.

Nested Class Summary
- Nested classes/interfaces inherited from class org.json.stream.JSONStreamReader
  JSONStreamReader.ParseState

Field Summary
- Fields inherited from class org.json.stream.JSONStreamReader
  bufferedAppender, lexer, objectStack, state

Constructor Summary

Constructors
Constructor and Description
`JSONLimitStreamReader(java.io.InputStream inputStream, java.nio.charset.Charset charset)` Construct a `JSONStreamReader` from an `InputStream` and a supplied `Charset`.
`JSONLimitStreamReader(java.io.Reader reader)` Construct a `JSONStreamReader` from a `Reader`.
`JSONLimitStreamReader(java.lang.String s)` Construct a `JSONStreamReader` from a `String`.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`<T extends java.lang.Appendable> T`	`appendNextNumberValue(T writer)` If the `ParseState` was `JSONStreamReader.ParseState.NUMBER_VALUE`, append the number sequence to the given `Appendable`.
`java.math.BigDecimal`	`nextBigDecimalValue()` If the `ParseState` was `JSONStreamReader.ParseState.NUMBER_VALUE`, return the value as a `BigDecimal`.
`java.math.BigInteger`	`nextBigIntegerValue()` If the `ParseState` was `JSONStreamReader.ParseState.NUMBER_VALUE`, return the value as a `BigInteger`.
`double`	`nextDoubleValue()` If the `ParseState` was `JSONStreamReader.ParseState.NUMBER_VALUE`, return the value as a double.
`int`	`nextIntValue()` If the `ParseState` was `JSONStreamReader.ParseState.NUMBER_VALUE`, return the value as an int.
`java.lang.String`	`nextKey()` If the `ParseState` was `JSONStreamReader.ParseState.KEY`, return the text of the key name.
`long`	`nextLongValue()` If the `ParseState` was `JSONStreamReader.ParseState.NUMBER_VALUE`, return the value as a long.
`java.lang.Number`	`nextNumberValue()` If the `ParseState` was `JSONStreamReader.ParseState.NUMBER_VALUE`, return the value as a `Number`.
`java.lang.String`	`nextStringValue()` If the `ParseState` was `JSONStreamReader.ParseState.STRING_VALUE`, return the value as a `String`.
`java.lang.Object`	`nextValue()` If the `ParseState` was `JSONStreamReader.ParseState.NULL_VALUE`, `JSONStreamReader.ParseState.BOOLEAN_VALUE`, `JSONStreamReader.ParseState.NUMBER_VALUE`, or `JSONStreamReader.ParseState.STRING_VALUE`, return the value as an `Object`.
`void`	`setExponentDigits(int exponentDigits)` The maximum number of exponent digits in a number.
`void`	`setKeyLength(int keyLength)` The maximum length of any key.
`void`	`setMantissaDigits(int mantissaDigits)` The maximum number of mantissa digits in a number.
`void`	`setStringLength(int stringLength)` The maximum length of any string value.
`java.lang.String`	`toString()` Returns a string representation of the stream reader, including its current position in the source stream.
`JSONLimitStreamReader`	`withLimits(BuilderLimits limits)` Set keyLength, stringLength, mantissaDigits, and exponentDigits using values from the supplied `BuilderLimits` object.

Methods inherited from class org.json.stream.JSONStreamReader
appendNextStringValue, currentState, decodeBigDecimal, decodeBigInteger, decodeDouble, decodeInt, decodeLong, decodeNull, decodeNumber, getParsePosition, getStackDepth, hasNext, nextBooleanValue, nextNullValue, nextState, skipToEndStructure

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - JSONLimitStreamReader
```
public JSONLimitStreamReader(java.io.Reader reader)
```
    Construct a JSONStreamReader from a Reader.
    
    Parameters:
    
    reader - A reader.
  - JSONLimitStreamReader
```
public JSONLimitStreamReader(java.io.InputStream inputStream,
                             java.nio.charset.Charset charset)
```
    Construct a JSONStreamReader from an InputStream and a supplied Charset.
    
    Parameters:
    
    inputStream - the input stream containing the JSON data
    
    charset - the character set with which to interpret the input stream
  - JSONLimitStreamReader
```
public JSONLimitStreamReader(java.lang.String s)
```
    Construct a JSONStreamReader from a String.
    
    Parameters:
    
    s - A source string.
- Method Detail
  - withLimits
```
public JSONLimitStreamReader withLimits(BuilderLimits limits)
```
    Set keyLength, stringLength, mantissaDigits, and exponentDigits using values from the supplied BuilderLimits object.
    See BuilderLimits.secureDefaults() for some practical limits.
    
    Parameters:
    
    limits - the limits to be set
    
    Returns:
    
    this object
  - setKeyLength
```
public void setKeyLength(int keyLength)
```
    The maximum length of any key.
    
    Parameters:
    
    keyLength - the maximum length of any key
  - setStringLength
```
public void setStringLength(int stringLength)
```
    The maximum length of any string value.
    
    Parameters:
    
    stringLength - the maximum length of any string value
  - setMantissaDigits
```
public void setMantissaDigits(int mantissaDigits)
```
    The maximum number of mantissa digits in a number.
    
    Parameters:
    
    mantissaDigits - the maximum number of mantissa digits of any number value
  - setExponentDigits
```
public void setExponentDigits(int exponentDigits)
```
    The maximum number of exponent digits in a number. May be 0 to indicate integer-only values.
    
    Parameters:
    
    exponentDigits - the maximum number of exponent digits of any number value
  - nextKey
```
public java.lang.String nextKey()
                         throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.KEY, return the text of the key name.
    This method advances the parser onto the next state.
    
    Overrides:
    
    nextKey in class JSONStreamReader
    
    Returns:
    
    the parsed text of the key
    
    Throws:
    
    JSONException - there was a problem with the source stream
  - nextValue
```
public java.lang.Object nextValue()
                           throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NULL_VALUE, JSONStreamReader.ParseState.BOOLEAN_VALUE, JSONStreamReader.ParseState.NUMBER_VALUE, or JSONStreamReader.ParseState.STRING_VALUE, return the value as an Object. The values that can be returned here are:
    - JSONObject.NULL
    - Boolean.TRUE or Boolean.FALSE
    - A Double, Long, Integer, BigInteger, or BigDecimal
    - A String
    This method advances the parser onto the next state.
    Overrides:
    
    nextValue in class JSONStreamReader
    
    Returns:
    
    an Object of the type described above
    
    Throws:
    
    JSONException
  - nextStringValue
```
public java.lang.String nextStringValue()
                                 throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.STRING_VALUE, return the value as a String.
    This method advances the parser onto the next state.
    
    Overrides:
    
    nextStringValue in class JSONStreamReader
    
    Returns:
    
    a String value
    
    Throws:
    
    JSONException
  - nextNumberValue
```
public java.lang.Number nextNumberValue()
                                 throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NUMBER_VALUE, return the value as a Number.
    The number type returned is one of:
    - A Double
    - A Long
    - An Integer
    - A BigDecimal
    - A BigInteger
    This method advances the parser onto the next state.
    Overrides:
    
    nextNumberValue in class JSONStreamReader
    
    Returns:
    
    a value that is a subclass of the Number class
    
    Throws:
    
    JSONException
  - appendNextNumberValue
```
public <T extends java.lang.Appendable> T appendNextNumberValue(T writer)
                                                         throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NUMBER_VALUE, append the number sequence to the given Appendable.
    This method is suitable for cases where the caller wishes to perform their own conversion of number values into a corresponding Object type.
    
    This method advances the parser onto the next state.
    
    Overrides:
    
    appendNextNumberValue in class JSONStreamReader
    
    Type Parameters:
    
    T - the type of Appendable, returned to the caller
    
    Parameters:
    
    writer - the writer to which the number sequence will be written
    
    Returns:
    
    the given Appendable object
    
    Throws:
    
    JSONException
  - nextBigDecimalValue
```
public java.math.BigDecimal nextBigDecimalValue()
                                         throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NUMBER_VALUE, return the value as a BigDecimal.
    This method advances the parser onto the next state.
    
    Overrides:
    
    nextBigDecimalValue in class JSONStreamReader
    
    Returns:
    
    a number value as a BigDecimal class
    
    Throws:
    
    JSONException
  - nextBigIntegerValue
```
public java.math.BigInteger nextBigIntegerValue()
                                         throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NUMBER_VALUE, return the value as a BigInteger.
    If the JSON value is not parseable as a big integer, as defined by the JSON grammar, a JSONException will be thrown.
    
    This method advances the parser onto the next state.
    
    Overrides:
    
    nextBigIntegerValue in class JSONStreamReader
    
    Returns:
    
    a number value as a BigInteger class
    
    Throws:
    
    JSONException
  - nextDoubleValue
```
public double nextDoubleValue()
                       throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NUMBER_VALUE, return the value as a double.
    This method advances the parser onto the next state.
    
    Overrides:
    
    nextDoubleValue in class JSONStreamReader
    
    Returns:
    
    a double value
    
    Throws:
    
    JSONException
  - nextIntValue
```
public int nextIntValue()
                 throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NUMBER_VALUE, return the value as an int.
    If the JSON value is not parseable as an int, as defined by the JSON grammar, a JSONException will be thrown.
    
    This method advances the parser onto the next state.
    
    Overrides:
    
    nextIntValue in class JSONStreamReader
    
    Returns:
    
    an int value
    
    Throws:
    
    JSONException
  - nextLongValue
```
public long nextLongValue()
                   throws JSONException
```
    If the ParseState was JSONStreamReader.ParseState.NUMBER_VALUE, return the value as a long.
    If the JSON value is not parseable as a long, as defined by the JSON grammar, a JSONException will be thrown.
    
    This method advances the parser onto the next state.
    
    Overrides:
    
    nextLongValue in class JSONStreamReader
    
    Returns:
    
    a long value
    
    Throws:
    
    JSONException
  - toString
```
public java.lang.String toString()
```
    Returns a string representation of the stream reader, including its current position in the source stream.
    
    Overrides:
    
    toString in class JSONStreamReader

Class JSONLimitStreamReader

Nested Class Summary

Nested classes/interfaces inherited from class org.json.stream.JSONStreamReader

Field Summary

Fields inherited from class org.json.stream.JSONStreamReader

Constructor Summary

Method Summary

Methods inherited from class org.json.stream.JSONStreamReader

Methods inherited from class java.lang.Object

Constructor Detail

JSONLimitStreamReader

JSONLimitStreamReader

JSONLimitStreamReader

Method Detail

withLimits

setKeyLength

setStringLength

setMantissaDigits

setExponentDigits

nextKey

nextValue

nextStringValue

nextNumberValue

appendNextNumberValue

nextBigDecimalValue

nextBigIntegerValue

nextDoubleValue

nextIntValue

nextLongValue

toString