java.lang.Object
- ch.qos.logback.core.spi.ContextAwareBase
- - ch.qos.logback.core.encoder.EncoderBase<ILoggingEvent>
  - - ch.qos.logback.classic.encoder.JsonEncoder

All Implemented Interfaces:

Encoder<ILoggingEvent>, ContextAware, LifeCycle
```
public class JsonEncoder
extends EncoderBase<ILoggingEvent>
```
JSON encoder that produces one JSON object per line in JSON Lines format, suitable for structured logging. Each ILoggingEvent is encoded into a JSON object containing fields such as timestamp, level, message, and optional elements like MDC properties, markers, and stack traces.
This encoder supports extensive configuration through boolean flags to include or exclude specific fields in the output, allowing customization for different logging needs. For example, you can enable/disable sequence numbers, nanoseconds, thread names, logger context, markers, MDC, key-value pairs, arguments, and throwable information.

The encoder is designed for extensibility: subclasses can override protected methods (e.g., appendLoggerContext(java.lang.StringBuilder, ch.qos.logback.classic.spi.LoggerContextVO), appendThrowableProxy(java.lang.StringBuilder, java.lang.String, ch.qos.logback.classic.spi.IThrowableProxy), appendMarkers(java.lang.StringBuilder, ch.qos.logback.classic.spi.ILoggingEvent)) to customize how specific parts of the JSON are generated. Additionally, the appendCustomFields(java.lang.StringBuilder, ch.qos.logback.classic.spi.ILoggingEvent) hook allows appending custom top-level fields to the JSON object.

Configuration

Use the setter methods (e.g., setWithSequenceNumber(boolean), setWithTimestamp(boolean)) to control which fields are included. By default, most fields are enabled except withFormattedMessage.

Example Usage
```
 <appender name="JSON" class="ch.qos.logback.core.ConsoleAppender">
   <encoder class="ch.qos.logback.classic.encoder.JsonEncoder">
     <withSequenceNumber>false</withSequenceNumber>
     <withNanoseconds>false</withNanoseconds>
     <withThreadName>false</withThreadName>
   </encoder>
 </appender>
 
```
This produces output similar to the following (on a single line):
```
{"timestamp":1640995200000,"level":"INFO","loggerName":"com.example.MyClass","context":{"name":"default","birthdate":1640995200000,"properties":{}},"message":"Hello World"}
```
Since:

1.3.8/1.4.8

Author:

Ceki Gülcü

See Also:

JSON Lines, RFC 8259 (The JavaScript Object Notation (JSON) Data Interchange Format), EncoderBase

Field Summary

Fields
Modifier and Type	Field	Description
`static String`	`ARGUMENT_ARRAY_ATTR_NAME`
`static String`	`BIRTHDATE_ATTR_NAME`
`static String`	`CAUSE_ATTR_NAME`
`static String`	`CLASS_NAME_ATTR_NAME`
`protected static char`	`CLOSE_ARRAY`
`protected static char`	`CLOSE_OBJ`
`protected static String`	`COL_SP`
`static String`	`COMMON_FRAMES_COUNT_ATTR_NAME`
`static String`	`CONTEXT_ATTR_NAME`
`static String`	`CONTEXT_PROPERTIES_ATTR_NAME`
`protected static char`	`ENTRY_SEPARATOR`
`static String`	`FORMATTED_MESSAGE_ATTR_NAME`
`static String`	`KEY_VALUE_PAIRS_ATTR_NAME`
`static String`	`LEVEL_ATTR_NAME`
`static String`	`LOGGER_ATTR_NAME`
`static String`	`MARKERS_ATTR_NAME`
`static String`	`MDC_ATTR_NAME`
`static String`	`MESSAGE_ATTR_NAME`
`static String`	`METHOD_NAME_ATTR_NAME`
`static String`	`NAME_ATTR_NAME`
`static String`	`NANOSECONDS_ATTR_NAME`
`protected static char`	`OPEN_ARRAY`
`protected static char`	`OPEN_OBJ`
`protected static char`	`QUOTE`
`protected static String`	`QUOTE_COL`
`static String`	`SEQUENCE_NUMBER_ATTR_NAME`
`protected static char`	`SP`
`static String`	`STEP_ARRAY_NAME_ATTRIBUTE`
`static String`	`SUPPRESSED_ATTR_NAME`
`static String`	`THREAD_NAME_ATTR_NAME`
`static String`	`THROWABLE_ATTR_NAME`
`static String`	`TIMESTAMP_ATTR_NAME`
`protected static char`	`VALUE_SEPARATOR`

Fields inherited from class ch.qos.logback.core.encoder.EncoderBase
started

Fields inherited from class ch.qos.logback.core.spi.ContextAwareBase
context

Constructor Summary

Constructors
Constructor Description

JsonEncoder()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`appendArgumentArray(StringBuilder sb, ILoggingEvent event)`
`protected void`	`appendCustomFields(StringBuilder sb, ILoggingEvent event)`	Hook allowing subclasses to append additional fields into the root JSON object.
`protected void`	`appenderMember(StringBuilder sb, String key, String value)`
`protected void`	`appenderMemberWithIntValue(StringBuilder sb, String key, int value)`
`protected void`	`appenderMemberWithLongValue(StringBuilder sb, String key, long value)`
`protected void`	`appendKeyValuePairs(StringBuilder sb, ILoggingEvent event)`
`protected void`	`appendLoggerContext(StringBuilder sb, LoggerContextVO loggerContextVO)`
`protected void`	`appendMap(StringBuilder sb, String attrName, Map<String,String> map)`
`protected void`	`appendMarkers(StringBuilder sb, ILoggingEvent event)`
`protected void`	`appendMDC(StringBuilder sb, ILoggingEvent event)`
`protected void`	`appendSTEPArray(StringBuilder sb, StackTraceElementProxy[] stepArray, int commonFrames)`
`protected void`	`appendThrowableProxy(StringBuilder sb, String attributeName, IThrowableProxy itp)`
`protected void`	`appendThrowableProxy(StringBuilder sb, String attributeName, IThrowableProxy itp, boolean appendValueSeparator)`
`protected void`	`appendValueSeparator(StringBuilder sb, boolean... subsequentConditionals)`	Append a JSON value separator (a comma) to the provided `StringBuilder` when any of the supplied boolean flags indicate that a subsequent element is present.
`byte[]`	`encode(ILoggingEvent event)`	Encode an event as bytes.
`byte[]`	`footerBytes()`	Get footer bytes.
`byte[]`	`headerBytes()`	Get header bytes.
`void`	`setWithArguments(boolean withArguments)`	Enable or disable the inclusion of the event argument array in the encoded output.
`void`	`setWithContext(boolean withContext)`	Enable or disable the inclusion of the logger context information.
`void`	`setWithFormattedMessage(boolean withFormattedMessage)`	Enable or disable the inclusion of the formatted message in the encoded output.
`void`	`setWithKVPList(boolean withKVPList)`	Enable or disable the inclusion of key-value pairs attached to the logging event.
`void`	`setWithLevel(boolean withLevel)`	Enable or disable the inclusion of the log level in the encoded output.
`void`	`setWithLoggerName(boolean withLoggerName)`	Enable or disable the inclusion of the logger name in the encoded output.
`void`	`setWithMarkers(boolean withMarkers)`	Enable or disable the inclusion of markers in the encoded output.
`void`	`setWithMDC(boolean withMDC)`	Enable or disable the inclusion of MDC properties in the encoded output.
`void`	`setWithMessage(boolean withMessage)`	Enable or disable the inclusion of the raw message text in the encoded output.
`void`	`setWithNanoseconds(boolean withNanoseconds)`	Set whether nanoseconds will be included in the timestamp output.
`void`	`setWithSequenceNumber(boolean withSequenceNumber)`	Set whether the sequence number is included in each encoded event.
`void`	`setWithThreadName(boolean withThreadName)`	Enable or disable the inclusion of the thread name in the encoded output.
`void`	`setWithThrowable(boolean withThrowable)`	Enable or disable the inclusion of throwable information in the encoded output.
`void`	`setWithTimestamp(boolean withTimestamp)`	Set whether the event timestamp is included in each encoded event.

Methods inherited from class ch.qos.logback.core.encoder.EncoderBase
isStarted, start, stop

Methods inherited from class ch.qos.logback.core.spi.ContextAwareBase
addError, addError, addInfo, addInfo, addStatus, addWarn, addWarn, getContext, getDeclaredOrigin, getStatusManager, setContext

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

Methods inherited from interface ch.qos.logback.core.spi.ContextAware
addError, addError, addInfo, addInfo, addStatus, addWarn, addWarn, getContext, setContext

- Field Detail
  - CONTEXT_ATTR_NAME
```
public static final String CONTEXT_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - NAME_ATTR_NAME
```
public static final String NAME_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - BIRTHDATE_ATTR_NAME
```
public static final String BIRTHDATE_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - CONTEXT_PROPERTIES_ATTR_NAME
```
public static final String CONTEXT_PROPERTIES_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - TIMESTAMP_ATTR_NAME
```
public static final String TIMESTAMP_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - NANOSECONDS_ATTR_NAME
```
public static final String NANOSECONDS_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - SEQUENCE_NUMBER_ATTR_NAME
```
public static final String SEQUENCE_NUMBER_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - LEVEL_ATTR_NAME
```
public static final String LEVEL_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - MARKERS_ATTR_NAME
```
public static final String MARKERS_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - THREAD_NAME_ATTR_NAME
```
public static final String THREAD_NAME_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - MDC_ATTR_NAME
```
public static final String MDC_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - LOGGER_ATTR_NAME
```
public static final String LOGGER_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - MESSAGE_ATTR_NAME
```
public static final String MESSAGE_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - FORMATTED_MESSAGE_ATTR_NAME
```
public static final String FORMATTED_MESSAGE_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - ARGUMENT_ARRAY_ATTR_NAME
```
public static final String ARGUMENT_ARRAY_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - KEY_VALUE_PAIRS_ATTR_NAME
```
public static final String KEY_VALUE_PAIRS_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - THROWABLE_ATTR_NAME
```
public static final String THROWABLE_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - CAUSE_ATTR_NAME
```
public static final String CAUSE_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - SUPPRESSED_ATTR_NAME
```
public static final String SUPPRESSED_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - COMMON_FRAMES_COUNT_ATTR_NAME
```
public static final String COMMON_FRAMES_COUNT_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - CLASS_NAME_ATTR_NAME
```
public static final String CLASS_NAME_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - METHOD_NAME_ATTR_NAME
```
public static final String METHOD_NAME_ATTR_NAME
```
    See Also:
    
    Constant Field Values
  - STEP_ARRAY_NAME_ATTRIBUTE
```
public static final String STEP_ARRAY_NAME_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - OPEN_OBJ
```
protected static final char OPEN_OBJ
```
    See Also:
    
    Constant Field Values
  - CLOSE_OBJ
```
protected static final char CLOSE_OBJ
```
    See Also:
    
    Constant Field Values
  - OPEN_ARRAY
```
protected static final char OPEN_ARRAY
```
    See Also:
    
    Constant Field Values
  - CLOSE_ARRAY
```
protected static final char CLOSE_ARRAY
```
    See Also:
    
    Constant Field Values
  - QUOTE
```
protected static final char QUOTE
```
    See Also:
    
    Constant Field Values
  - SP
```
protected static final char SP
```
    See Also:
    
    Constant Field Values
  - ENTRY_SEPARATOR
```
protected static final char ENTRY_SEPARATOR
```
    See Also:
    
    Constant Field Values
  - COL_SP
```
protected static final String COL_SP
```
    See Also:
    
    Constant Field Values
  - QUOTE_COL
```
protected static final String QUOTE_COL
```
    See Also:
    
    Constant Field Values
  - VALUE_SEPARATOR
```
protected static final char VALUE_SEPARATOR
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - JsonEncoder
```
public JsonEncoder()
```
- Method Detail
  - headerBytes
```
public byte[] headerBytes()
```
    Description copied from interface: Encoder
    
    Get header bytes. This method is typically called upon opening of an output stream.
    
    Returns:
    
    header bytes. Null values are allowed.
  - encode
```
public byte[] encode(ILoggingEvent event)
```
    Description copied from interface: Encoder
    
    Encode an event as bytes.
  - appendValueSeparator
```
protected void appendValueSeparator(StringBuilder sb,
                                    boolean... subsequentConditionals)
```
    Append a JSON value separator (a comma) to the provided StringBuilder when any of the supplied boolean flags indicate that a subsequent element is present.
    Callers pass a sequence of booleans that represent whether subsequent JSON members will be written. If at least one of those booleans is true, this method appends a single comma (',') to separate JSON fields.
    
    This method is protected so subclasses that extend the encoder can reuse or override the logic for inserting separators between generated JSON members.
    
    Parameters:
    
    sb - the StringBuilder to append the separator to; must not be null
    
    subsequentConditionals - one or more booleans indicating whether subsequent JSON elements will be written. If any value is true, a comma is appended.
  - appendLoggerContext
```
protected void appendLoggerContext(StringBuilder sb,
                                   LoggerContextVO loggerContextVO)
```
  - appendMap
```
protected void appendMap(StringBuilder sb,
                         String attrName,
                         Map<String,String> map)
```
  - appendThrowableProxy
```
protected void appendThrowableProxy(StringBuilder sb,
                                    String attributeName,
                                    IThrowableProxy itp)
```
  - appendThrowableProxy
```
protected void appendThrowableProxy(StringBuilder sb,
                                    String attributeName,
                                    IThrowableProxy itp,
                                    boolean appendValueSeparator)
```
  - appendSTEPArray
```
protected void appendSTEPArray(StringBuilder sb,
                               StackTraceElementProxy[] stepArray,
                               int commonFrames)
```
  - appendCustomFields
```
protected void appendCustomFields(StringBuilder sb,
                                  ILoggingEvent event)
```
    Hook allowing subclasses to append additional fields into the root JSON object. Default implementation is a no-op.
    Subclasses may append additional top-level JSON members here. If a subclass writes additional members it should prepend them with VALUE_SEPARATOR (a comma) if necessary to keep the JSON valid. Implementations must not close the root JSON object or write the final line separator; JsonEncoder handles those.
    
    Parameters:
    
    sb - the StringBuilder that accumulates the JSON output; never null
    
    event - the logging event being encoded; never null
  - appenderMember
```
protected void appenderMember(StringBuilder sb,
                              String key,
                              String value)
```
  - appenderMemberWithIntValue
```
protected void appenderMemberWithIntValue(StringBuilder sb,
                                          String key,
                                          int value)
```
  - appenderMemberWithLongValue
```
protected void appenderMemberWithLongValue(StringBuilder sb,
                                           String key,
                                           long value)
```
  - appendKeyValuePairs
```
protected void appendKeyValuePairs(StringBuilder sb,
                                   ILoggingEvent event)
```
  - appendArgumentArray
```
protected void appendArgumentArray(StringBuilder sb,
                                   ILoggingEvent event)
```
  - appendMarkers
```
protected void appendMarkers(StringBuilder sb,
                             ILoggingEvent event)
```
  - appendMDC
```
protected void appendMDC(StringBuilder sb,
                         ILoggingEvent event)
```
  - footerBytes
```
public byte[] footerBytes()
```
    Description copied from interface: Encoder
    
    Get footer bytes. This method is typically called prior to the closing of the stream where events are written.
    
    Returns:
    
    footer bytes. Null values are allowed.
  - setWithSequenceNumber
```
public void setWithSequenceNumber(boolean withSequenceNumber)
```
    Set whether the sequence number is included in each encoded event.
    
    Parameters:
    
    withSequenceNumber - true to include the sequence number in the output
    
    Since:
    
    1.5.0
  - setWithTimestamp
```
public void setWithTimestamp(boolean withTimestamp)
```
    Set whether the event timestamp is included in each encoded event.
    
    Parameters:
    
    withTimestamp - true to include the event timestamp in the output
    
    Since:
    
    1.5.0
  - setWithNanoseconds
```
public void setWithNanoseconds(boolean withNanoseconds)
```
    Set whether nanoseconds will be included in the timestamp output.
    
    Parameters:
    
    withNanoseconds - true to include nanoseconds in the timestamp output
    
    Since:
    
    1.5.0
  - setWithLevel
```
public void setWithLevel(boolean withLevel)
```
    Enable or disable the inclusion of the log level in the encoded output.
    
    Parameters:
    
    withLevel - true to include the log level. Default is true.
  - setWithThreadName
```
public void setWithThreadName(boolean withThreadName)
```
    Enable or disable the inclusion of the thread name in the encoded output.
    
    Parameters:
    
    withThreadName - true to include the thread name. Default is true.
  - setWithLoggerName
```
public void setWithLoggerName(boolean withLoggerName)
```
    Enable or disable the inclusion of the logger name in the encoded output.
    
    Parameters:
    
    withLoggerName - true to include the logger name. Default is true.
  - setWithContext
```
public void setWithContext(boolean withContext)
```
    Enable or disable the inclusion of the logger context information.
    
    Parameters:
    
    withContext - true to include the logger context. Default is true.
  - setWithMarkers
```
public void setWithMarkers(boolean withMarkers)
```
    Enable or disable the inclusion of markers in the encoded output.
    
    Parameters:
    
    withMarkers - true to include markers. Default is true.
  - setWithMDC
```
public void setWithMDC(boolean withMDC)
```
    Enable or disable the inclusion of MDC properties in the encoded output.
    
    Parameters:
    
    withMDC - true to include MDC properties. Default is true.
  - setWithKVPList
```
public void setWithKVPList(boolean withKVPList)
```
    Enable or disable the inclusion of key-value pairs attached to the logging event.
    
    Parameters:
    
    withKVPList - true to include the key/value pairs list. Default is true.
  - setWithMessage
```
public void setWithMessage(boolean withMessage)
```
    Enable or disable the inclusion of the raw message text in the encoded output.
    
    Parameters:
    
    withMessage - true to include the message. Default is true.
  - setWithArguments
```
public void setWithArguments(boolean withArguments)
```
    Enable or disable the inclusion of the event argument array in the encoded output.
    
    Parameters:
    
    withArguments - true to include the argument array. Default is true.
  - setWithThrowable
```
public void setWithThrowable(boolean withThrowable)
```
    Enable or disable the inclusion of throwable information in the encoded output.
    
    Parameters:
    
    withThrowable - true to include throwable/stacktrace information. Default is true.
  - setWithFormattedMessage
```
public void setWithFormattedMessage(boolean withFormattedMessage)
```
    Enable or disable the inclusion of the formatted message in the encoded output.
    
    Parameters:
    
    withFormattedMessage - true to include the formatted message. Default is false.

Class JsonEncoder

Configuration

Example Usage

Field Summary

Fields inherited from class ch.qos.logback.core.encoder.EncoderBase

Fields inherited from class ch.qos.logback.core.spi.ContextAwareBase

Constructor Summary

Method Summary

Methods inherited from class ch.qos.logback.core.encoder.EncoderBase

Methods inherited from class ch.qos.logback.core.spi.ContextAwareBase

Methods inherited from class java.lang.Object

Methods inherited from interface ch.qos.logback.core.spi.ContextAware

Field Detail

CONTEXT_ATTR_NAME

NAME_ATTR_NAME

BIRTHDATE_ATTR_NAME

CONTEXT_PROPERTIES_ATTR_NAME

TIMESTAMP_ATTR_NAME

NANOSECONDS_ATTR_NAME

SEQUENCE_NUMBER_ATTR_NAME

LEVEL_ATTR_NAME

MARKERS_ATTR_NAME

THREAD_NAME_ATTR_NAME

MDC_ATTR_NAME

LOGGER_ATTR_NAME

MESSAGE_ATTR_NAME

FORMATTED_MESSAGE_ATTR_NAME

ARGUMENT_ARRAY_ATTR_NAME

KEY_VALUE_PAIRS_ATTR_NAME

THROWABLE_ATTR_NAME

CAUSE_ATTR_NAME

SUPPRESSED_ATTR_NAME

COMMON_FRAMES_COUNT_ATTR_NAME

CLASS_NAME_ATTR_NAME

METHOD_NAME_ATTR_NAME

STEP_ARRAY_NAME_ATTRIBUTE

OPEN_OBJ

CLOSE_OBJ

OPEN_ARRAY

CLOSE_ARRAY

QUOTE

SP

ENTRY_SEPARATOR

COL_SP

QUOTE_COL

VALUE_SEPARATOR

Constructor Detail

JsonEncoder

Method Detail

headerBytes

encode

appendValueSeparator

appendLoggerContext

appendMap

appendThrowableProxy

appendThrowableProxy

appendSTEPArray

appendCustomFields

appenderMember

appenderMemberWithIntValue

appenderMemberWithLongValue

appendKeyValuePairs

appendArgumentArray

appendMarkers

appendMDC

footerBytes

setWithSequenceNumber

setWithTimestamp

setWithNanoseconds

setWithLevel

setWithThreadName

setWithLoggerName

setWithContext

setWithMarkers

setWithMDC

setWithKVPList

setWithMessage

setWithArguments

setWithThrowable

setWithFormattedMessage