cn.trinea.android.common.util

Class ListUtils

java.lang.Object

cn.trinea.android.common.util.ListUtils

public class ListUtils
extends java.lang.Object

List Utils

Author:

Trinea 2011-7-22

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_JOIN_SEPARATOR default join separator

Constructor Summary

Constructors

Constructor and Description
ListUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static <V> boolean	addDistinctEntry(java.util.List<V> sourceList, V entry) add distinct entry to list
static <V> int	addDistinctList(java.util.List<V> sourceList, java.util.List<V> entryList) add all distinct entry to list1 from list2
static <V> boolean	addListNotNullValue(java.util.List<V> sourceList, V value) add not null entry to list
static <V> int	distinctList(java.util.List<V> sourceList) remove duplicate entries in list
static <V> V	getLast(java.util.List<V> sourceList, V value)
static <V> V	getNext(java.util.List<V> sourceList, V value)
static <V> int	getSize(java.util.List<V> sourceList) get size of list getSize(null) = 0; getSize({}) = 0; getSize({1}) = 1;
static <V> java.util.List<V>	invertList(java.util.List<V> sourceList) invert list
static <V> boolean	isEmpty(java.util.List<V> sourceList) is null or its size is 0 isEmpty(null) = true; isEmpty({}) = true; isEmpty({1}) = false;
static <V> boolean	isEquals(java.util.ArrayList<V> actual, java.util.ArrayList<V> expected) compare two list isEquals(null, null) = true; isEquals(new ArrayList<String>(), null) = false; isEquals(null, new ArrayList<String>()) = false; isEquals(new ArrayList<String>(), new ArrayList<String>()) = true;
static java.lang.String	join(java.util.List<java.lang.String> list) join list to string, separator is "," join(null) = ""; join({}) = ""; join({a,b}) = "a,b";
static java.lang.String	join(java.util.List<java.lang.String> list, char separator) join list to string join(null, '#') = ""; join({}, '#') = ""; join({a,b,c}, ' ') = "abc"; join({a,b,c}, '#') = "a#b#c";
static java.lang.String	join(java.util.List<java.lang.String> list, java.lang.String separator) join list to string. if separator is null, use DEFAULT_JOIN_SEPARATOR join(null, "#") = ""; join({}, "#$") = ""; join({a,b,c}, null) = "a,b,c"; join({a,b,c}, "") = "abc"; join({a,b,c}, "#") = "a#b#c"; join({a,b,c}, "#$") = "a#$b#$c";

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_JOIN_SEPARATOR

public static final java.lang.String DEFAULT_JOIN_SEPARATOR

default join separator

See Also:

Constant Field Values

Constructor Detail

ListUtils

public ListUtils()

Method Detail

getSize

public static <V> int getSize(java.util.List<V> sourceList)

get size of list

 getSize(null)   =   0;
 getSize({})     =   0;
 getSize({1})    =   1;
 

Type Parameters:

V -

Parameters:

sourceList -

Returns:

if list is null or empty, return 0, else return List.size().

isEmpty

public static <V> boolean isEmpty(java.util.List<V> sourceList)

is null or its size is 0

 isEmpty(null)   =   true;
 isEmpty({})     =   true;
 isEmpty({1})    =   false;
 

Type Parameters:

V -

Parameters:

sourceList -

Returns:

if list is null or its size is 0, return true, else return false.

isEquals

public static <V> boolean isEquals(java.util.ArrayList<V> actual,
                   java.util.ArrayList<V> expected)

compare two list

 isEquals(null, null) = true;
 isEquals(new ArrayList<String>(), null) = false;
 isEquals(null, new ArrayList<String>()) = false;
 isEquals(new ArrayList<String>(), new ArrayList<String>()) = true;
 

Type Parameters:

V -

Parameters:

actual -

expected -

Returns:

join

public static java.lang.String join(java.util.List<java.lang.String> list)

join list to string, separator is ","

 join(null)      =   "";
 join({})        =   "";
 join({a,b})     =   "a,b";
 

Parameters:

list -

Returns:

join list to string, separator is ",". if list is empty, return ""

join

public static java.lang.String join(java.util.List<java.lang.String> list,
                    char separator)

join list to string

 join(null, '#')     =   "";
 join({}, '#')       =   "";
 join({a,b,c}, ' ')  =   "abc";
 join({a,b,c}, '#')  =   "a#b#c";
 

Parameters:

list -

separator -

Returns:

join list to string. if list is empty, return ""

join

public static java.lang.String join(java.util.List<java.lang.String> list,
                    java.lang.String separator)

join list to string. if separator is null, use DEFAULT_JOIN_SEPARATOR

 join(null, "#")     =   "";
 join({}, "#$")      =   "";
 join({a,b,c}, null) =   "a,b,c";
 join({a,b,c}, "")   =   "abc";
 join({a,b,c}, "#")  =   "a#b#c";
 join({a,b,c}, "#$") =   "a#$b#$c";
 

Parameters:

list -

separator -

Returns:

join list to string with separator. if list is empty, return ""

addDistinctEntry

public static <V> boolean addDistinctEntry(java.util.List<V> sourceList,
                           V entry)

add distinct entry to list

Type Parameters:

V -

Parameters:

sourceList -

entry -

Returns:

if entry already exist in sourceList, return false, else add it and return true.

addDistinctList

public static <V> int addDistinctList(java.util.List<V> sourceList,
                      java.util.List<V> entryList)

add all distinct entry to list1 from list2

Type Parameters:

V -

Parameters:

sourceList -

entryList -

Returns:

the count of entries be added

distinctList

public static <V> int distinctList(java.util.List<V> sourceList)

remove duplicate entries in list

Type Parameters:

V -

Parameters:

sourceList -

Returns:

the count of entries be removed

addListNotNullValue

public static <V> boolean addListNotNullValue(java.util.List<V> sourceList,
                              V value)

add not null entry to list

Parameters:

sourceList -

value -

Returns:

• if sourceList is null, return false
• if value is null, return false
• return List.add(Object)

getLast

public static <V> V getLast(java.util.List<V> sourceList,
            V value)

See Also:

ArrayUtils#getLast(Object[], Object, Object, boolean)} defaultValue is null, isCircle is true

getNext

public static <V> V getNext(java.util.List<V> sourceList,
            V value)

See Also:

ArrayUtils#getNext(Object[], Object, Object, boolean)} defaultValue is null, isCircle is true

invertList

public static <V> java.util.List<V> invertList(java.util.List<V> sourceList)

invert list

Type Parameters:

V -

Parameters:

sourceList -

Returns: