Package org.codehaus.jettison.json
Class JSONWriter
- java.lang.Object
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- org.codehaus.jettison.json.JSONWriter
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- Direct Known Subclasses:
JSONStringer
public class JSONWriter extends java.lang.Object
JSONWriter provides a quick and convenient way of producing JSON text. The texts produced strictly conform to JSON syntax rules. No whitespace is added, so the results are ready for transmission or storage. Each instance of JSONWriter can produce one JSON text.A JSONWriter instance provides a
value
method for appending values to the text, and akey
method for adding keys before values in objects. There arearray
andendArray
methods that make and bound array values, andobject
andendObject
methods which make and bound object values. All of these methods return the JSONWriter instance, permitting a cascade style. For example,new JSONWriter(myWriter) .object() .key("JSON") .value("Hello, World!") .endObject();
which writes{"JSON":"Hello, World!"}
The first method called must be
array
orobject
. There are no methods for adding commas or colons. JSONWriter adds them for you. Objects and arrays can be nested up to 20 levels deep.This can sometimes be easier than using a JSONObject to build a string.
- Version:
- 2
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Field Summary
Fields Modifier and Type Field Description private boolean
comma
The comma flag determines if a comma should be output before the next value.private static int
maxdepth
protected char
mode
The current mode.private char[]
stack
The object/array stack.private int
top
The stack top index.protected java.io.Writer
writer
The writer that will receive the output.
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Constructor Summary
Constructors Constructor Description JSONWriter(java.io.Writer w)
Make a fresh JSONWriter.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description private JSONWriter
append(java.lang.String s)
Append a value.JSONWriter
array()
Begin appending a new array.private JSONWriter
end(char m, char c)
End something.JSONWriter
endArray()
End an array.JSONWriter
endObject()
End an object.JSONWriter
key(java.lang.String s)
Append a key.JSONWriter
object()
Begin appending a new object.private void
pop(char c)
Pop an array or object scope.private void
push(char c)
Push an array or object scope.JSONWriter
value(boolean b)
Append either the valuetrue
or the valuefalse
.JSONWriter
value(double d)
Append a double value.JSONWriter
value(long l)
Append a long value.JSONWriter
value(java.lang.Object o)
Append an object value.
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Field Detail
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maxdepth
private static final int maxdepth
- See Also:
- Constant Field Values
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comma
private boolean comma
The comma flag determines if a comma should be output before the next value.
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mode
protected char mode
The current mode. Values: 'a' (array), 'd' (done), 'i' (initial), 'k' (key), 'o' (object).
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stack
private char[] stack
The object/array stack.
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top
private int top
The stack top index. A value of 0 indicates that the stack is empty.
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writer
protected java.io.Writer writer
The writer that will receive the output.
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Method Detail
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append
private JSONWriter append(java.lang.String s) throws JSONException
Append a value.- Parameters:
s
- A string value.- Returns:
- this
- Throws:
JSONException
- If the value is out of sequence.
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array
public JSONWriter array() throws JSONException
Begin appending a new array. All values until the balancingendArray
will be appended to this array. TheendArray
method must be called to mark the array's end.- Returns:
- this
- Throws:
JSONException
- If the nesting is too deep, or if the object is started in the wrong place (for example as a key or after the end of the outermost array or object).
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end
private JSONWriter end(char m, char c) throws JSONException
End something.- Parameters:
m
- Modec
- Closing character- Returns:
- this
- Throws:
JSONException
- If unbalanced.
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endArray
public JSONWriter endArray() throws JSONException
End an array. This method most be called to balance calls toarray
.- Returns:
- this
- Throws:
JSONException
- If incorrectly nested.
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endObject
public JSONWriter endObject() throws JSONException
End an object. This method most be called to balance calls toobject
.- Returns:
- this
- Throws:
JSONException
- If incorrectly nested.
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key
public JSONWriter key(java.lang.String s) throws JSONException
Append a key. The key will be associated with the next value. In an object, every value must be preceded by a key.- Parameters:
s
- A key string.- Returns:
- this
- Throws:
JSONException
- If the key is out of place. For example, keys do not belong in arrays or if the key is null.
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object
public JSONWriter object() throws JSONException
Begin appending a new object. All keys and values until the balancingendObject
will be appended to this object. TheendObject
method must be called to mark the object's end.- Returns:
- this
- Throws:
JSONException
- If the nesting is too deep, or if the object is started in the wrong place (for example as a key or after the end of the outermost array or object).
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pop
private void pop(char c) throws JSONException
Pop an array or object scope.- Parameters:
c
- The scope to close.- Throws:
JSONException
- If nesting is wrong.
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push
private void push(char c) throws JSONException
Push an array or object scope.- Parameters:
c
- The scope to open.- Throws:
JSONException
- If nesting is too deep.
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value
public JSONWriter value(boolean b) throws JSONException
Append either the valuetrue
or the valuefalse
.- Parameters:
b
- A boolean.- Returns:
- this
- Throws:
JSONException
- JSONException
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value
public JSONWriter value(double d) throws JSONException
Append a double value.- Parameters:
d
- A double.- Returns:
- this
- Throws:
JSONException
- If the number is not finite.
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value
public JSONWriter value(long l) throws JSONException
Append a long value.- Parameters:
l
- A long.- Returns:
- this
- Throws:
JSONException
- JSONException
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value
public JSONWriter value(java.lang.Object o) throws JSONException
Append an object value.- Parameters:
o
- The object to append. It can be null, or a Boolean, Number, String, JSONObject, or JSONArray, or an object with a toJSONString() method.- Returns:
- this
- Throws:
JSONException
- If the value is out of sequence.
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