BlogJava-断点-随笔分类-Apache

DateUtils

断点 — Sun, 25 Jul 2010 03:02:00 GMT

DateUtils.compareYear(regDate, base.getTInsrncBgnTm()) // 新旧车标志【保险起期 - 初登年月】单位：年

断点 2010-07-25 11:02 发表评论

StringUtils

断点 — Sun, 30 May 2010 02:46:00 GMT

--项目中的用法。
1、StringUtils.join
List dwVoListInTab = this.prodService.getPicTabVOList(picId);
List dwNameListInTab = new ArrayList();
        for (PrdTabVO dwVo : dwVoListInTab) {
          String dwName = this.prodService.cvtTabNo2DWName(useProdNo, picId,
            dwVo.getCTabNo());
          dwNameListInTab.add(dwName);
          dwNameMap.put(dwVo.getCNmeEn(), dwName);
        }
        ((List)plyDwNameList).addAll(dwNameListInTab);

String dwNameListStr = "['" + StringUtils.join(dwNameListInTab.toArray(), "','") + "']";
其它：
StringUtils.join(new String[]{"cat","dog","carrot","leaf","door"}, ":")
// cat:dog:carrot:leaf:door

2、StringUtils.isNotEmpty    //Checks if a String is not empty ("") and not null.
if (StringUtils.isNotEmpty(onload))
          onload = sub.replace(onload);
        else {
          onload = "";
        }

public String replace(char oldChar,char newChar)返回一个新的字符串，它是通过用 newChar 替换此字符串中出现的所有 oldChar 得到的。
如果 oldChar 在此 String 对象表示的字符序列中没有出现，则返回对此 String 对象的引用。

3、StringUtils.equals    //StringUtils.equals(null, null)   = true
if (!StringUtils.equals(prodKindNo, "00")) {
}

4、StringUtils.isBlank     //Checks if a String is whitespace, empty ("") or null.
if (StringUtils.isBlank(taskId))
        jsBuffer.append("var taskId='';\n");
      else {
        jsBuffer.append("var taskId='" + taskId + "';\n");
      }

5、StringUtils.leftPad(String str, int size,String padStr) --左填充
//投保年度【保险起期 - 初登年月】单位：年
String ply_year = StringUtils.leftPad(String.valueOf(DateUtils.compareYear(regDate,base.getTInsrncBgnTm())), 2, '0');
/**
4260         *

Left pad a String with a specified String.

4261 *
4262 *

Pad to a size of size.

4263 *
4264 *



4265         * StringUtils.leftPad(null, *, *)      = null

4266         * StringUtils.leftPad("", 3, "z")      = "zzz"

4267         * StringUtils.leftPad("bat", 3, "yz")  = "bat"

4268         * StringUtils.leftPad("bat", 5, "yz")  = "yzbat"

4269         * StringUtils.leftPad("bat", 8, "yz")  = "yzyzybat"

4270         * StringUtils.leftPad("bat", 1, "yz")  = "bat"

4271         * StringUtils.leftPad("bat", -1, "yz") = "bat"

4272         * StringUtils.leftPad("bat", 5, null)  = "  bat"

4273         * StringUtils.leftPad("bat", 5, "")    = "  bat"

4274         *

4275         *
4276         * @param str the String to pad out, may be null
4277         * @param size the size to pad to
4278         * @param padStr the String to pad with, null or empty treated as single space
4279         * @return left padded String or original String if no padding is necessary,
4280         * null if null String input
4281         */
4282        public static String leftPad(String str, int size, String padStr) {
4283            if (str == null) {
4284                return null;
4285            }
4286            if (isEmpty(padStr)) {
4287                padStr = " ";
4288            }
4289            int padLen = padStr.length();
4290            int strLen = str.length();
4291            int pads = size - strLen;
4292            if (pads <= 0) {
4293                return str; // returns original String when possible
4294            }
4295            if (padLen == 1 && pads <= PAD_LIMIT) {
4296                return leftPad(str, size, padStr.charAt(0));
4297            }
4298
4299            if (pads == padLen) {
4300                return padStr.concat(str);
4301            } else if (pads < padLen) {
4302                return padStr.substring(0, pads).concat(str);
4303            } else {
4304                char[] padding = new char[pads];
4305                char[] padChars = padStr.toCharArray();
4306                for (int i = 0; i < pads; i++) {
4307                    padding[i] = padChars[i % padLen];
4308                }
4309                return new String(padding).concat(str);
4310            }
4311        }

---------------------------------------------

详见：http://commons.apache.org/lang/api/org/apache/commons/lang/StringUtils.html

isEmpty
public static boolean isEmpty(CharSequence str)
Checks if a String is empty ("") or null.

StringUtils.isEmpty(null)      = true
StringUtils.isEmpty("")        = true
StringUtils.isEmpty(" ")       = false
StringUtils.isEmpty("bob")     = false
StringUtils.isEmpty(" bob ") = false

NOTE: This method changed in Lang version 2.0. It no longer trims the String. That

functionality is available in isBlank().

Parameters:
str - the String to check, may be null
Returns:
true if the String is empty or null

isNotEmpty
public static boolean isNotEmpty(CharSequence str)
Checks if a String is not empty ("") and not null.

StringUtils.isNotEmpty(null)      = false
StringUtils.isNotEmpty("")        = false
StringUtils.isNotEmpty(" ")       = true
StringUtils.isNotEmpty("bob")     = true
StringUtils.isNotEmpty(" bob ") = true

Parameters:
str - the String to check, may be null
Returns:
true if the String is not empty and not null

isBlank
public static boolean isBlank(CharSequence str)
Checks if a String is whitespace, empty ("") or null.

StringUtils.isBlank(null)      = true
StringUtils.isBlank("")        = true
StringUtils.isBlank(" ")       = true
StringUtils.isBlank("bob")     = false
StringUtils.isBlank(" bob ") = false

Parameters:
str - the String to check, may be null
Returns:
true if the String is null, empty or whitespace
Since:
2.0

isNotBlank
public static boolean isNotBlank(CharSequence str)
Checks if a String is not empty (""), not null and not whitespace only.

StringUtils.isNotBlank(null)      = false
StringUtils.isNotBlank("")        = false
StringUtils.isNotBlank(" ")       = false
StringUtils.isNotBlank("bob")     = true
StringUtils.isNotBlank(" bob ") = true

Parameters:
str - the String to check, may be null
Returns:
true if the String is not empty and not null and not whitespace
Since:
2.0

trim
public static String trim(String str)
Removes control characters (char <= 32) from both ends of this String, handling null by

returning null.

The String is trimmed using String.trim(). Trim removes start and end characters <= 32.

To strip whitespace use strip(String).

To trim your choice of characters, use the strip(String, String) methods.

StringUtils.trim(null)          = null
StringUtils.trim("")            = ""
StringUtils.trim("     ")       = ""
StringUtils.trim("abc")         = "abc"
StringUtils.trim("    abc    ") = "abc"

Parameters:
str - the String to be trimmed, may be null
Returns:
the trimmed string, null if null String input

trimToNull
public static String trimToNull(String str)
Removes control characters (char <= 32) from both ends of this String returning null if

the String is empty ("") after the trim or if it is null.

The String is trimmed using String.trim(). Trim removes start and end characters <= 32.

To strip whitespace use stripToNull(String).

StringUtils.trimToNull(null)          = null
StringUtils.trimToNull("")            = null
StringUtils.trimToNull("     ")       = null
StringUtils.trimToNull("abc")         = "abc"
StringUtils.trimToNull("    abc    ") = "abc"

Parameters:
str - the String to be trimmed, may be null
Returns:
the trimmed String, null if only chars <= 32, empty or null String input
Since:
2.0

trimToEmpty
public static String trimToEmpty(String str)
Removes control characters (char <= 32) from both ends of this String returning an empty

String ("") if the String is empty ("") after the trim or if it is null.

The String is trimmed using String.trim(). Trim removes start and end characters <= 32.

To strip whitespace use stripToEmpty(String).

StringUtils.trimToEmpty(null)          = ""
StringUtils.trimToEmpty("")            = ""
StringUtils.trimToEmpty("     ")       = ""
StringUtils.trimToEmpty("abc")         = "abc"
StringUtils.trimToEmpty("    abc    ") = "abc"

Parameters:
str - the String to be trimmed, may be null
Returns:
the trimmed String, or an empty String if null input
Since:
2.0
equals
public static boolean equals(String str1,
String str2)
Compares two Strings, returning true if they are equal.

nulls are handled without exceptions. Two null references are considered to be equal. The

comparison is case sensitive.

StringUtils.equals(null, null) = true
StringUtils.equals(null, "abc") = false
StringUtils.equals("abc", null) = false
StringUtils.equals("abc", "abc") = true
StringUtils.equals("abc", "ABC") = false

Parameters:
str1 - the first String, may be null
str2 - the second String, may be null
Returns:
true if the Strings are equal, case sensitive, or both null
See Also:
String.equals(Object)

startsWith
public static boolean startsWith(String str,
String prefix)
Check if a String starts with a specified prefix.

nulls are handled without exceptions. Two null references are considered to be equal. The

comparison is case sensitive.

StringUtils.startsWith(null, null) = true
StringUtils.startsWith(null, "abc") = false
StringUtils.startsWith("abcdef", null) = false
StringUtils.startsWith("abcdef", "abc") = true
StringUtils.startsWith("ABCDEF", "abc") = false

Parameters:
str - the String to check, may be null
prefix - the prefix to find, may be null
Returns:
true if the String starts with the prefix, case sensitive, or both null
Since:
2.4
See Also:
String.startsWith(String)

1.去除尾部换行符，使用函数：StringUtils.chomp(testString)
函数介绍:去除testString尾部的换行符
例程:
String input = "Hello\n";
System.out.println( StringUtils.chomp( input ));
String input2 = "Another test\r\n";
System.out.println( StringUtils.chomp( input2 ));

输出如下:
Hello
Another test

2.判断字符串内容的类型，函数介绍：
StringUtils.isNumeric( testString ) :如果testString全由数字组成返回True
StringUtils.isAlpha( testString ) :如果testString全由字母组成返回True
StringUtils.isAlphanumeric( testString ) :如果testString全由数字或数字组成返回True
StringUtils.isAlphaspace( testString ) :如果testString全由字母或空格组成返回True

例程:
String state = "Virginia";
System.out.println( "Is state number? " + StringUtils.isNumeric(state ) );
System.out.println( "Is state alpha? " + StringUtils.isAlpha( state ));
System.out.println( "Is state alphanumeric? " +StringUtils.isAlphanumeric( state ) );
System.out.println( "Is state alphaspace? " + StringUtils.isAlphaSpace( state ) );

输出如下:
    Is state number? false
    Is state alpha? true
    Is state alphanumeric? true
    Is state alphaspace? true

3.查找嵌套字符串，使用函数：
StringUtils.substringBetween(testString,header,tail)
函数介绍：在testString中取得header和tail之间的字符串。不存在则返回空
例程：
String htmlContent = "ABC1234ABC4567";
System.out.println(StringUtils.substringBetween(htmlContent, "1234", "4567"));
System.out.println(StringUtils.substringBetween(htmlContent, "12345", "4567"));

输出如下：
ABC
null

4.颠倒字符串，使用函数：StringUtils.reverse(testString)
函数介绍:得到testString中字符颠倒后的字符串
例程:
System.out.println( StringUtils.reverse("ABCDE"));

输出如下:
EDCBA

5.部分截取字符串，使用函数：
StringUtils.substringBetween(testString,fromString,toString ):取得两字符之间的字符串
StringUtils.substringAfter( ):取得指定字符串后的字符串
StringUtils.substringBefore( )：取得指定字符串之前的字符串
StringUtils.substringBeforeLast( )：取得最后一个指定字符串之前的字符串
StringUtils.substringAfterLast( )：取得最后一个指定字符串之后的字符串

函数介绍：上面应该都讲明白了吧。
例程：
String formatted = " 25 * (30,40) [50,60] | 30";
System.out.print("N0: " + StringUtils.substringBeforeLast( formatted, "*" ) );
System.out.print(", N1: " + StringUtils.substringBetween( formatted, "(", "," ) );
System.out.print(", N2: " + StringUtils.substringBetween( formatted, ",", ")" ) );
System.out.print(", N3: " + StringUtils.substringBetween( formatted, "[", "," ) );
System.out.print(", N4: " + StringUtils.substringBetween( formatted, ",", "]" ) );
System.out.print(", N5: " + StringUtils.substringAfterLast( formatted, "|" ) );

输出如下：
N0: 25 , N1: 30, N2: 40, N3: 50, N4: 40) [50,60, N5: 30

断点 2010-05-30 10:46 发表评论

MethodUtils

断点 — Sun, 30 May 2010 02:01:00 GMT

MethodUtils的简单用法。

package com.ztf;

import java.util.Map;

import org.apache.commons.beanutils.MethodUtils;
import org.apache.commons.beanutils.PropertyUtils;

public class TestMethodUtils {
        public static void main(String[] args) throws Exception{

            Entity entity = new Entity();
            entity.setId(1) ;
            entity.setName("断点");

           // 通过MethodUtils的invokeMethod方法,执行指定的entity中的方法(无参的情况)
            MethodUtils.invokeMethod(entity, "sayHello", null);

            // 通过MethodUtils的invokeMethod方法,执行指定的entity中的方法（1参的情况）
            MethodUtils.invokeMethod(entity, "sayHello", "断点");

            // 通过MethodUtils的invokeMethod方法,执行指定的entity中的方法（多参的情况）
            Object[] params = new Object[]{new Integer(10),new Integer(12)};
            MethodUtils.invokeMethod(entity, "sayHello", params);
        }
}

实体：

package com.ztf;

public class Entity {
    private Integer id;
    private String name;

    public void sayHello(){
        System.out.println("sayHello()---> 无参");
    }

    public void sayHello(String s){
        System.out.println("sayHello()---> 有1个参数" );
    }

    public void sayHello(Integer a,Integer b){
        System.out.println("sayHello()---> 有2个参数");
    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
}

输出：
sayHello()---> 无参
sayHello()---> 有1个参数
sayHello()---> 有2个参数

断点 2010-05-30 10:01 发表评论

PropertyUtils

断点 — Sun, 30 May 2010 01:51:00 GMT

实体bean。

package com.ztf;
import java.util.Map;

import org.apache.commons.beanutils.MethodUtils;
import org.apache.commons.beanutils.PropertyUtils;

public class TestPropertyUtils {
        public static void main(String[] args) throws Exception{

            Entity entity = new Entity();
            entity.setId(1) ;
            entity.setName("断点");

            // 通过PropertyUtils的getProperty方法获取指定属性的值
            Integer id = (Integer)PropertyUtils.getProperty(entity, "id");
            String name = (String)PropertyUtils.getProperty(entity, "name");
            System.out.println("id = " + id + "  name = " + name);

            // 调用PropertyUtils的setProperty方法设置entity的指定属性
            PropertyUtils.setProperty(entity, "name", "每天进步一点");
            System.out.println("name = " + entity.getName());

            // 通过PropertyUtils的describe方法把entity的所有属性与属性值封装进Map中
            Map map = PropertyUtils.describe(entity);
            System.out.println("id = " + map.get("id") + "  name = " + map.get("name"));

                  }
}

输出：
id = 1 name = 断点
name = 每天进步一点
id = 1 name = 每天进步一点

其它例子：
import org.apache.commons.beanutils.PropertyUtils;
List> data = new ArrayList>();
for(BaseGrpMemberVO member : MemberVO){
          Map m = new HashMap();
          for(Map.Entry entry: fieldMap.entrySet()){
                    String key = entry.getKey();
                    fieldList.add(key); //记录字段名
                    String[] keyArray = key.split("\\.");
                    if(keyArray.length == 2){//成员信息
                        Object o =PropertyUtils.getProperty(member, keyArray[1]);
                        m.put(key, o==null?"":o.toString());
                    }else if(keyArray.length == 3){//险别信息
                        List cvrgVoList = mgr.getRelCvrgById(member.getCPkId());
                        String cvrgNo = keyArray[0];
                        for(BaseGrpCvrgVO cvrgVo : cvrgVoList){
                            if(cvrgNo.equals(cvrgVo.getCCvrgNo())){
                                Object o =PropertyUtils.getProperty(cvrgVo, keyArray[2]);
                                m.put(key, o==null?"":o.toString());
                            }
                        }
                    }
                }
          data.add(m);
       }

断点 2010-05-30 09:51 发表评论

BeanUtils

断点 — Sun, 30 May 2010 01:25:00 GMT

apache.commons.beanutils.BeanUtils
该class提供了一系列的静态方法操作已存在的符合JavaBean规范定义的Java Class.这里强调的JavaBean规范,简单来说就是一个Java Class通过一系列getter和setter的方法向外界展示其内在的成员变量(属性)。

通过BeanUtils的静态方法,我们可以:
复制一个JavaBean的实例--BeanUtils.cloneBean();
在一个JavaBean的两个实例之间复制属性--BeanUtils.copyProperties(),BeanUtils.copyProperty();
为一个JavaBean的实例设置成员变量(属性)值--BeanUtils.populate(),BeanUtils.setProperty();
从一个JavaBean的实例中读取成员变量(属性)的值--BeanUtils.getArrayProperty(),BeanUtils.getIndexedProperty(),BeanUtils.getMappedProperty(),BeanUtils.getNestedProperty(),BeanUtils.getSimpleProperty(),BeanUtils.getProperty(),BeanUtils.describe();

1、BeanUtils.cloneBean(java.lang.object bean)
为bean创建一个clone对象,方法返回类型为Object.此方法的实现机制建立在bean提供的一系列的getters和setters的基础之上.此方法的正常使用代码非常简单,故略掉.

2、BeanUtils.copyProperties(java.lang.Object dest, java.lang.Object orig)
一个bean class有两个实例:orig和dest,将orig中的成员变量的值复制给dest,即将已经存在的dest变为orig的副本.与BeanUtils.cloneBean(java.lang.object bean)的区别就在于是不是需要创建新的实例了.
原文如下:Copy property values from the origin bean to the destination bean for all cases where the property names are the same.

3、BeanUtils.setProperty(java.lang.Object bean,java.lang.String name,java.lang.Object value)
这个方法简单的说就是将bean中的成员变量name赋值为value.

BeanUtils.populate(java.lang.Object bean, java.util.Map properties)
使用一个map为bean赋值,该map中的key的名称与bean中的成员变量名称相对应.注意:只有在key和成员变量名称完全对应的时候,populate机制才发生作用;但是在数量上没有任何要求,如map中的key如果是成员变量名称的子集,那么成员变量中有的而map中不包含的项将会保留默认值;同样,如果成员变量是map中key的子集,那么多余的key不会对populate的结果产生任何影响.恩,结果就是populate只针对map中key名称集合与bean中成员变量名称集合的交集产生作用。

4、BeanUtils.getArrayProperty(java.lang.Object bean,java.lang.String name)
获取bean中数组成员变量(属性)的值.
如果我们指定的name不是数组类型的成员变量,结果会如何?会不会抛出类型错误的exception呢?回答是不会,仍然会返回一个String的数组,数组的第一项就是name对应的值(如果不

是String类型的话,JVM会自动的调用toString()方法的).

BeanUtils.getIndexedProperty(java.lang.Object bean,java.lang.String name)
BeanUtils.getIndexedProperty(java.lang.Object bean,java.lang.String name,int index)
这两个方法都是获取数组成员变量(属性)中的单一元素值的方法.
比如,我想得到SampleObject中words[1]的值,用法如下:
BeanUtils.getIndexedProperty(sampleOjbectInstance,"words[1]");
BeanUtils.getIndexedProperty(sampleOjbectInstance,"words",1);

BeanUtils.getMappedProperty(java.lang.Object bean,java.lang.String name)
BeanUtils.getMappedProperty(java.lang.Object bean,java.lang.String name,java.lang.String key)

BeanUtils.describe(java.lang.Object bean)
将一个bean以map的形式展示。

来源：http://www.chinaitpower.com/A/2005-07-03/150232.html

断点 2010-05-30 09:25 发表评论

ArrayUtils 的使用

断点 — Mon, 17 May 2010 15:57:00 GMT

ArrayUtils类帮我们完成数组的打印、查找、克隆、倒序、以及值型/对象数组之间的转换等操作。

1import org.apache.commons.lang.ArrayUtils;
2
3public class TestArrayUtils {
4
5    public static void main(String[] args) {
6        /**
7         * 打印数组中的内容
8         */
9        int[] intArray = new int[] { 2, 3, 4, 5, 6 };
10        int[][] multiDimension = new int[][] { { 1, 2, 3 }, { 2, 3 }, {5, 6, 7} };
11
12        System.out.println( "intArray: " + ArrayUtils.toString( intArray ) );
13        System.out.println( "multiDimension: " + ArrayUtils.toString( multiDimension ) );
14    }
15}

输出：
intArray: {2,3,4,5,6}
multiDimension: {{1,2,3},{2,3},{5,6,7}}

断点 2010-05-17 23:57 发表评论

CollectionUtils 的使用

断点 — Mon, 17 May 2010 15:29:00 GMT

CollectionUtils 中四个方法对集合操作： union()，intersection()，disjunction();，subtract()。

1import java.util.Arrays;
2import java.util.Collection;
3import java.util.Collections;
4import java.util.List;
5
6import org.apache.commons.collections.CollectionUtils;
7import org.apache.commons.lang.ArrayUtils;
8
9public class TestCollectionUtils {
10 @SuppressWarnings("unchecked")
11 public static void main(String[] args) {
12  String[] arrayA = new String[] { "1", "2", "3", "3", "4", "5" };
13  String[] arrayB = new String[] { "3", "4", "4", "5", "6", "7" };
14
15  List<String> a = Arrays.asList(arrayA);
16  List<String> b = Arrays.asList(arrayB);
17  // 并集
18  Collection<String> union = CollectionUtils.union(a, b);
19  // 交集
20  Collection<String> intersection = CollectionUtils.intersection(a, b);
21  // 交集的补集
22  Collection<String> disjunction = CollectionUtils.disjunction(a, b);
23  // 集合相减
24  Collection<String> subtract = CollectionUtils.subtract(a, b);
25
26  Collections.sort((List<String>) union);
27  Collections.sort((List<String>) intersection);
28  Collections.sort((List<String>) disjunction);
29  Collections.sort((List<String>) subtract);
30
31  System.out.println("A: " + ArrayUtils.toString(a.toArray()));
32  System.out.println("B: " + ArrayUtils.toString(b.toArray()));
33  System.out.println("--------------------------------------------");
34  System.out.println("Union(A, B): " + ArrayUtils.toString(union.toArray()));
35  System.out.println("Intersection(A, B): " + ArrayUtils.toString(intersection.toArray()));
36  System.out.println("Disjunction(A, B): " + ArrayUtils.toString(disjunction.toArray()));
37  System.out.println("Subtract(A, B): " + ArrayUtils.toString(subtract.toArray()));
38 }
39}

输出：
A: {1,2,3,3,4,5}
B: {3,4,4,5,6,7}
--------------------------------------------
Union(A, B): {1,2,3,3,4,4,5,6,7}
Intersection(A, B): {3,4,5}
Disjunction(A, B): {1,2,3,4,6,7}
Subtract(A, B): {1,2,3}

转载：http://blog.csdn.net/ofofw/archive/2009/06/26/4300964.aspx

断点 2010-05-17 23:29 发表评论