com.diffplug.common.base

Class FieldsAndGetters

java.lang.Object

com.diffplug.common.base.FieldsAndGetters

public class FieldsAndGetters
extends Object

Utilities for obtaining the fields and getter methods of an object using reflection. Useful for first-pass debugging of runtime objects.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FieldsAndGetters.ObjectIsNull Sentinel class for null objects.

Constructor Summary

Constructors

Constructor and Description
FieldsAndGetters()

Method Summary

Modifier and Type	Method and Description
static void	dumpAll(String name, Object obj) Dumps all fields and getters of obj to System.out.
static void	dumpAll(String name, Object obj, StringPrinter printer) Dumps all fields and getters of obj to printer.
static void	dumpIf(String name, Object obj, Predicate<String> evalPredicate, Predicate<Map.Entry<String,Object>> dumpPredicate, StringPrinter printer) Passes each field and getter of obj to evalPredicate, grabs its value if it passes, and if the value passes dumpPredicate then it is dumped to printer.
static void	dumpNonNull(String name, Object obj) Dumps all non-null fields and getters of obj to System.out.
static void	dumpNonNull(String name, Object obj, StringPrinter printer) Dumps all non-null fields and getters of obj to printer.
static Stream<Map.Entry<Field,Object>>	fields(Object obj) Returns a Stream of all public fields and their values for the given object.
static Stream<Map.Entry<Field,Object>>	fields(Object obj, Predicate<Field> predicate) Returns a Stream of all public fields which match predicate and their values for the given object.
static Stream<Map.Entry<String,Object>>	fieldsAndGetters(Object obj) Returns a Stream of all public fields and getter methods and their values for the given object.
static Stream<Map.Entry<String,Object>>	fieldsAndGetters(Object obj, Predicate<String> predicate) Returns a Stream of all public fields and getter methods which match predicate and their values for the given object.
static Stream<Map.Entry<Method,Object>>	getters(Object obj) Returns a Stream of all public getter methods and their return values for the given object.
static Stream<Map.Entry<Method,Object>>	getters(Object obj, Predicate<Method> predicate) Returns a Stream of all public getter methods which match predicate and their return values for the given object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FieldsAndGetters

public FieldsAndGetters()

Method Detail

fields

public static Stream<Map.Entry<Field,Object>> fields(Object obj)

Returns a Stream of all public fields and their values for the given object.

See Also:

fields(Object, Predicate)

fields

public static Stream<Map.Entry<Field,Object>> fields(Object obj,
                                                     Predicate<Field> predicate)

Returns a Stream of all public fields which match predicate and their values for the given object.

This method uses reflection to find all of the public instance fields of the given object, and if they pass the given predicate, it includes them in a stream of Map.Entry<Field, Object> where the entry's value is the value of the field for this object.

getters

public static Stream<Map.Entry<Method,Object>> getters(Object obj)

Returns a Stream of all public getter methods and their return values for the given object.

See Also:

getters(Object, Predicate)

getters

public static Stream<Map.Entry<Method,Object>> getters(Object obj,
                                                       Predicate<Method> predicate)

Returns a Stream of all public getter methods which match predicate and their return values for the given object.

This method uses reflection to find all of the public instance methods which don't take any arguments and return a value. If they pass the given predicate, then they are called, and the return value is included in a stream of Map.Entry<Method, Object>.

Note that there are some methods which have the signature of a getter, but actually mutate the object being inspected, e.g. InputStream.read(). These will be called unless you manually exclude them using the predicate.

fieldsAndGetters

public static Stream<Map.Entry<String,Object>> fieldsAndGetters(Object obj)

Returns a Stream of all public fields and getter methods and their values for the given object.

See Also:

getters(Object, Predicate)

fieldsAndGetters

public static Stream<Map.Entry<String,Object>> fieldsAndGetters(Object obj,
                                                                Predicate<String> predicate)

Returns a Stream of all public fields and getter methods which match predicate and their values for the given object.

This method combines the results of fields(Object, Predicate) and getters(Object, Predicate). The Predicate<String> will be passed the field names and the getter names (which are postfixed by () to mark them as methods).

See Also:

fields(Object, Predicate), getters(Object, Predicate)

dumpIf

public static void dumpIf(String name,
                          Object obj,
                          Predicate<String> evalPredicate,
                          Predicate<Map.Entry<String,Object>> dumpPredicate,
                          StringPrinter printer)

Passes each field and getter of obj to evalPredicate, grabs its value if it passes, and if the value passes dumpPredicate then it is dumped to printer.

See Also:

fieldsAndGetters(Object, Predicate)

dumpAll

public static void dumpAll(String name,
                           Object obj)

Dumps all fields and getters of obj to System.out.

See Also:

dumpIf(java.lang.String, java.lang.Object, java.util.function.Predicate<java.lang.String>, java.util.function.Predicate<java.util.Map.Entry<java.lang.String, java.lang.Object>>, com.diffplug.common.base.StringPrinter)

dumpNonNull

public static void dumpNonNull(String name,
                               Object obj)

Dumps all non-null fields and getters of obj to System.out.

See Also:

dumpIf(java.lang.String, java.lang.Object, java.util.function.Predicate<java.lang.String>, java.util.function.Predicate<java.util.Map.Entry<java.lang.String, java.lang.Object>>, com.diffplug.common.base.StringPrinter)

dumpAll

public static void dumpAll(String name,
                           Object obj,
                           StringPrinter printer)

Dumps all fields and getters of obj to printer.

See Also:

dumpIf(java.lang.String, java.lang.Object, java.util.function.Predicate<java.lang.String>, java.util.function.Predicate<java.util.Map.Entry<java.lang.String, java.lang.Object>>, com.diffplug.common.base.StringPrinter)

dumpNonNull

public static void dumpNonNull(String name,
                               Object obj,
                               StringPrinter printer)

Dumps all non-null fields and getters of obj to printer.

See Also:

dumpIf(java.lang.String, java.lang.Object, java.util.function.Predicate<java.lang.String>, java.util.function.Predicate<java.util.Map.Entry<java.lang.String, java.lang.Object>>, com.diffplug.common.base.StringPrinter)