Java 如何拆分字符串，同时保留分隔符？

我有一个多行字符串，由一组不同的分隔符分隔：

(Text1)(DelimiterA)(Text2)(DelimiterC)(Text3)(DelimiterB)(Text4)

我可以使用

string.split

将该字符串拆分为多个部分，但似乎无法获得与分隔符regex匹配的实际字符串

换句话说，这就是我得到的：

• Text1

• Text2

• Text3

• Text4

这就是我想要的

• Text1

• DelimiterA

• Text2

• DelimiterC

• Text3

• DelimiterB

• Text4

---

有什么JDK方法可以使用分隔符regex分割字符串，但同时保留分隔符吗？

我对Java不太了解，但是如果你找不到一个可以这样做的分割方法，我建议你自己做

string[] mySplit(string s,string delimiter)
{
    string[] result = s.Split(delimiter);
    for(int i=0;i<result.Length-1;i++)
    {
        result[i] += delimiter; //this one would add the delimiter to each items end except the last item, 
                    //you can modify it however you want
    }
}
string[] res = mySplit(myString,myDelimiter);

string[]mySplit（字符串s，字符串分隔符）
{
字符串[]结果=s.Split（分隔符）；
对于（inti=0；i快速回答：使用像\b这样的非物理边界进行拆分。我将尝试并试验它是否有效（在PHP和JS中使用）

这是可能的，也是一种工作，但可能拆分太多。实际上，这取决于您要拆分的字符串和所需的结果。请提供更多详细信息，我们将更好地帮助您

另一种方法是进行自己的拆分，捕获分隔符（假设它是可变的），然后将其添加到结果中

我的快速测试：

String str = "'ab','cd','eg'";
String[] stra = str.split("\\b");
for (String s : stra) System.out.print(s + "|");
System.out.println();

结果:

'|ab|','|cd|','|eg|'|

有点太多了…：-）
我不知道Java API中有哪个函数可以实现这一点（这并不是说它不存在），但下面是我自己的实现（一个或多个分隔符将作为单个标记返回；如果希望每个分隔符作为单独的标记返回，则需要进行一些调整）：

static String[]splitWithDelimiters（字符串s）{
如果（s==null | | s.length（）==0）{
返回新字符串[0]；
}
LinkedList结果=新建LinkedList（）；
StringBuilder sb=null；
布尔wasLetterOrDigit=！Character.isleterOrdigit（s.charAt（0））；
for（char c:s.toCharArray（））{
if（字符.isLetterOrDigit（c）^wasletterdigit）{
如果（sb！=null）{
添加（sb.toString（））；
}
sb=新的StringBuilder（）；
WasletterDigit=！WasletterDigit；
}
sb.附加（c）；
}
添加（sb.toString（））；
返回result.toArray（新字符串[0]）；
}
我喜欢StringTokenizer的想法，因为它是可枚举的。

但它也是过时的，并被String.split替换，后者返回一个无聊的字符串[]（并且不包括分隔符）

所以我实现了一个StringTokenizerEx，它是一个Iterable，需要一个真正的regexp来拆分字符串

true regexp表示它不是重复形成分隔符的“字符序列”：

“o”将只匹配“o”，并将“ooo”拆分为三个分隔符，其中包含两个空字符串：

[o], '', [o], '', [o]

但是在拆分“aooob”时，regexp o+将返回预期结果

要使用此StringTokenizerEx，请执行以下操作：

final StringTokenizerEx aStringTokenizerEx = new StringTokenizerEx("boo:and:foo", "o+");
final String firstDelimiter = aStringTokenizerEx.getDelimiter();
for(String aString: aStringTokenizerEx )
{
    // uses the split String detected and memorized in 'aString'
    final nextDelimiter = aStringTokenizerEx.getDelimiter();
}

此类代码可从获取

对于响应（一个包含测试用例的自包含类），复制粘贴它（在“src/test”目录中）和运行它。它的main（）方法说明了不同的用法


注：（2009年末编辑）

这篇文章很好地解释了
String.split（）
中的奇怪行为

乔什·布洛赫甚至对这篇文章发表了评论：

是的，这很痛苦。FWIW，这样做有一个很好的理由：与Perl的兼容性。

做这件事的人是Mike“madbot”McCloskey，他现在和我们一起在Google工作。Mike确保Java的正则表达式几乎通过了每一个30K Perl正则表达式测试（并且运行得更快）

Google还包含一个拆分器，它是：


简单易用
由谷歌（而不是你）维护

所以它可能值得一看。从他们的：

JDK有以下特点：

如果您想确切了解它的功能，可以使用它：
-正则表达式
-结果作为数组
-它处理空碎片的方式

迷你拼图：“a，b，”。拆分（“，”）返回

答复：（e）上述任何一项

只跳过尾部的清空！（谁知道防止跳过的解决方法？很有趣…）

在任何情况下，我们的拆分器都更加灵活：默认行为过于简单：

如果你想要额外的功能，就去要求吧

配置方法的顺序并不重要——在拆分过程中，在检查是否为空之前进行修剪

import java.util.regex.*；
导入java.util.LinkedList；
公共类拆分器{
私有静态最终模式默认值\u Pattern=Pattern.compile（\\s+）；
私有模式；
私有布尔分隔符；
公共拆分器（模式、布尔分隔符）{
这个模式=模式；
this.keep_delimiters=keep_delimiters；
}
公共拆分器（字符串模式、布尔分隔符）{
这（Pattern.compile（Pattern==null？“：Pattern），保留分隔符）；
}
公共拆分器（模式）{this（模式，true）；}
公共拆分器（字符串模式）{this（模式，true）；}
公共拆分器（布尔保持分隔符）{this（默认模式，保持分隔符）}
公共拆分器（）{this（默认_模式）；}
公共字符串[]拆分（字符串文本）{
if（text==null）{
text=“”；
}
int last_match=0；
LinkedList splitted=新建LinkedList（）；
Matcher m=this.pattern.Matcher（文本）；
while（m.find（））{
拆分的.add（text.substring（最后一个匹配，m.start（））；
if（此.keep_分隔符）{
拆分。添加（m.group（））；
}
[], 'a', [ooo], 'b', []

final StringTokenizerEx aStringTokenizerEx = new StringTokenizerEx("boo:and:foo", "o+");
final String firstDelimiter = aStringTokenizerEx.getDelimiter();
for(String aString: aStringTokenizerEx )
{
    // uses the split String detected and memorized in 'aString'
    final nextDelimiter = aStringTokenizerEx.getDelimiter();
}

String[] pieces = "foo.bar".split("\\.");

(a) "", "a", "", "b", ""
(b) null, "a", null, "b", null
(c) "a", null, "b"
(d) "a", "b"
(e) None of the above

",a,,b,".split(",")
returns
"", "a", "", "b"

Splitter.on(',').split(" foo, ,bar, quux,")
--> [" foo", " ", "bar", " quux", ""]

Splitter.on(',')
.trimResults()
.omitEmptyStrings()
.split(" foo, ,bar, quux,")
--> ["foo", "bar", "quux"]

import java.util.regex.*;
import java.util.LinkedList;

public class Splitter {
    private static final Pattern DEFAULT_PATTERN = Pattern.compile("\\s+");

    private Pattern pattern;
    private boolean keep_delimiters;

    public Splitter(Pattern pattern, boolean keep_delimiters) {
        this.pattern = pattern;
        this.keep_delimiters = keep_delimiters;
    }
    public Splitter(String pattern, boolean keep_delimiters) {
        this(Pattern.compile(pattern==null?"":pattern), keep_delimiters);
    }
    public Splitter(Pattern pattern) { this(pattern, true); }
    public Splitter(String pattern) { this(pattern, true); }
    public Splitter(boolean keep_delimiters) { this(DEFAULT_PATTERN, keep_delimiters); }
    public Splitter() { this(DEFAULT_PATTERN); }

    public String[] split(String text) {
        if (text == null) {
            text = "";
        }

        int last_match = 0;
        LinkedList<String> splitted = new LinkedList<String>();

        Matcher m = this.pattern.matcher(text);

        while (m.find()) {

            splitted.add(text.substring(last_match,m.start()));

            if (this.keep_delimiters) {
                splitted.add(m.group());
            }

            last_match = m.end();
        }

        splitted.add(text.substring(last_match));

        return splitted.toArray(new String[splitted.size()]);
    }

    public static void main(String[] argv) {
        if (argv.length != 2) {
            System.err.println("Syntax: java Splitter <pattern> <text>");
            return;
        }

        Pattern pattern = null;
        try {
            pattern = Pattern.compile(argv[0]);
        }
        catch (PatternSyntaxException e) {
            System.err.println(e);
            return;
        }

        Splitter splitter = new Splitter(pattern);

        String text = argv[1];
        int counter = 1;
        for (String part : splitter.split(text)) {
            System.out.printf("Part %d: \"%s\"\n", counter++, part);
        }
    }
}

/*
    Example:
    > java Splitter "\W+" "Hello World!"
    Part 1: "Hello"
    Part 2: " "
    Part 3: "World"
    Part 4: "!"
    Part 5: ""
*/

Pattern p = Pattern.compile("(?<=\\w)(?=\\W)|(?<=\\W)(?=\\w)");
System.out.println(Arrays.toString(p.split("'ab','cd','eg'")));
System.out.println(Arrays.toString(p.split("boo:and:foo")));

[', ab, ',', cd, ',', eg, ']
[boo, :, and, :, foo]

{ "'", "ab", "','", "cd", "','", "eg", "'" }
{ "boo", ":", "and", ":", "foo" }

public class Split {
    public static List<String> split(String s, String pattern) {
        assert s != null;
        assert pattern != null;
        return split(s, Pattern.compile(pattern));
    }

    public static List<String> split(String s, Pattern pattern) {
        assert s != null;
        assert pattern != null;
        Matcher m = pattern.matcher(s);
        List<String> ret = new ArrayList<String>();
        int start = 0;
        while (m.find()) {
            ret.add(s.substring(start, m.start()));
            ret.add(m.group());
            start = m.end();
        }
        ret.add(start >= s.length() ? "" : s.substring(start));
        return ret;
    }

    private static void testSplit(String s, String pattern) {
        System.out.printf("Splitting '%s' with pattern '%s'%n", s, pattern);
        List<String> tokens = split(s, pattern);
        System.out.printf("Found %d matches%n", tokens.size());
        int i = 0;
        for (String token : tokens) {
            System.out.printf("  %d/%d: '%s'%n", ++i, tokens.size(), token);
        }
        System.out.println();
    }

    public static void main(String args[]) {
        testSplit("abcdefghij", "z"); // "abcdefghij"
        testSplit("abcdefghij", "f"); // "abcde", "f", "ghi"
        testSplit("abcdefghij", "j"); // "abcdefghi", "j", ""
        testSplit("abcdefghij", "a"); // "", "a", "bcdefghij"
        testSplit("abcdefghij", "[bdfh]"); // "a", "b", "c", "d", "e", "f", "g", "h", "ij"
    }
}

new StringTokenizer("Hello, world. Hi!", ",.!", true); // true for returnDelims

System.out.println(Arrays.toString("a;b;c;d".split("(?<=;)")));
System.out.println(Arrays.toString("a;b;c;d".split("(?=;)")));
System.out.println(Arrays.toString("a;b;c;d".split("((?<=;)|(?=;))")));
[a;, b;, c;, d]
[a, ;b, ;c, ;d]
[a, ;, b, ;, c, ;, d]
static public final String WITH_DELIMITER = "((?<=%1$s)|(?=%1$s))";
...
public void someMethod() {
...
final String[] aEach = "a;b;c;d".split(String.format(WITH_DELIMITER, ";"));
...
}
...

string.replace(FullString, "," , "~,~")

String str = "boo:and:foo";
str = str.replace(":","newdelimiter:");
String[] tokens = str.split("newdelimiter");

public class SplitNDump {
    static void dump(String[] arr) {
        for (String s : arr) {
            System.out.format("[%s]", s);
        }
        System.out.println();
    }
    public static void main(String[] args) {
        dump("1,234,567,890".split(","));
        // "[1][234][567][890]"
        dump("1,234,567,890".split("(?=,)"));   
        // "[1][,234][,567][,890]"
        dump("1,234,567,890".split("(?<=,)"));  
        // "[1,][234,][567,][890]"
        dump("1,234,567,890".split("(?<=,)|(?=,)"));
        // "[1][,][234][,][567][,][890]"

        dump(":a:bb::c:".split("(?=:)|(?<=:)"));
        // "[][:][a][:][bb][:][:][c][:]"
        dump(":a:bb::c:".split("(?=(?!^):)|(?<=:)"));
        // "[:][a][:][bb][:][:][c][:]"
        dump(":::a::::b  b::c:".split("(?=(?!^):)(?<!:)|(?!:)(?<=:)"));
        // "[:::][a][::::][b  b][::][c][:]"
        dump("a,bb:::c  d..e".split("(?!^)\\b"));
        // "[a][,][bb][:::][c][  ][d][..][e]"

        dump("ArrayIndexOutOfBoundsException".split("(?<=[a-z])(?=[A-Z])"));
        // "[Array][Index][Out][Of][Bounds][Exception]"
        dump("1234567890".split("(?<=\\G.{4})"));   
        // "[1234][5678][90]"

        // Split at the end of each run of letter
        dump("Boooyaaaah! Yippieeee!!".split("(?<=(?=(.)\\1(?!\\1))..)"));
        // "[Booo][yaaaa][h! Yipp][ieeee][!!]"
    }
}

String str = "Hello-World:How\nAre You&doing";
inputs = str.split("(?!^)\\b");
for (int i=0; i<inputs.length; i++) {
   System.out.println("a[" + i + "] = \"" + inputs[i] + '"');
}

a[0] = "Hello"
a[1] = "-"
a[2] = "World"
a[3] = ":"
a[4] = "How"
a[5] = "
"
a[6] = "Are"
a[7] = " "
a[8] = "You"
a[9] = "&"
a[10] = "doing"

// add match to the list
        matchList.add(input.subSequence(start, end).toString());

public static String[] inclusiveSplit(String input, String re, int limit) {
    int index = 0;
    boolean matchLimited = limit > 0;
    ArrayList<String> matchList = new ArrayList<String>();

    Pattern pattern = Pattern.compile(re);
    Matcher m = pattern.matcher(input);

    // Add segments before each match found
    while (m.find()) {
        int end = m.end();
        if (!matchLimited || matchList.size() < limit - 1) {
            int start = m.start();
            String match = input.subSequence(index, start).toString();
            matchList.add(match);
            // add match to the list
            matchList.add(input.subSequence(start, end).toString());
            index = end;
        } else if (matchList.size() == limit - 1) { // last one
            String match = input.subSequence(index, input.length())
                    .toString();
            matchList.add(match);
            index = end;
        }
    }

    // If no match was found, return this
    if (index == 0)
        return new String[] { input.toString() };

    // Add remaining segment
    if (!matchLimited || matchList.size() < limit)
        matchList.add(input.subSequence(index, input.length()).toString());

    // Construct result
    int resultSize = matchList.size();
    if (limit == 0)
        while (resultSize > 0 && matchList.get(resultSize - 1).equals(""))
            resultSize--;
    String[] result = new String[resultSize];
    return matchList.subList(0, resultSize).toArray(result);
}

String temp[]=str.split("\\W");
String temp2[]=str.split("\\w||\\s");
int i=0;
for(String string:temp)
System.out.println(string);
String temp3[]=new String[temp.length-1];
for(String string:temp2)
{
        System.out.println(string);
        if((string.equals("")!=true)&&(string.equals("\\s")!=true))
        {
                temp3[i]=string;
                i++;
        }
//      System.out.println(temp.length);
//      System.out.println(temp2.length);
}
System.out.println(temp3.length);
String[] temp4=new String[temp.length+temp3.length];
int j=0;
for(i=0;i<temp.length;i++)
{
        temp4[j]=temp[i];
        j=j+2;
}
j=1;
for(i=0;i<temp3.length;i++)
{
        temp4[j]=temp3[i];
        j+=2;
}
for(String s:temp4)
System.out.println(s);

List splitWithTokens(str, pat) {
    def tokens=[]
    def lastMatch=0
    def m = str=~pat
    while (m.find()) {
      if (m.start() > 0) tokens << str[lastMatch..<m.start()]
      tokens << m.group()
      lastMatch=m.end()
    }
    if (lastMatch < str.length()) tokens << str[lastMatch..<str.length()]
    tokens
}

[['<html><head><title>this is the title</title></head>',/<[^>]+>/],
 ['before<html><head><title>this is the title</title></head>after',/<[^>]+>/]
].each { 
   println splitWithTokens(*it)
}

StringTokenizer(String str, String delimiters, true);

public static String[] splitIncludeDelimeter(String regex, String text){
    List<String> list = new LinkedList<>();
    Matcher matcher = Pattern.compile(regex).matcher(text);

    int now, old = 0;
    while(matcher.find()){
        now = matcher.end();
        list.add(text.substring(old, now));
        old = now;
    }

    if(list.size() == 0)
        return new String[]{text};

    //adding rest of a text as last element
    String finalElement = text.substring(old);
    list.add(finalElement);

    return list.toArray(new String[list.size()]);
}

public static String[] splitIncludeDelimeter2(String regex, String text){
    List<String> list = new LinkedList<>();
    Matcher matcher = Pattern.compile(regex).matcher(text);

    StringBuffer stringBuffer = new StringBuffer();
    while(matcher.find()){
        matcher.appendReplacement(stringBuffer, matcher.group());
        list.add(stringBuffer.toString());
        stringBuffer.setLength(0); //clear buffer
    }

    matcher.appendTail(stringBuffer); ///dodajemy reszte  ciagu
    list.add(stringBuffer.toString());

    return list.toArray(new String[list.size()]);
}

    String expression = "((A+B)*C-D)*E";
    expression = expression.replaceAll("\\+", "~+~");
    expression = expression.replaceAll("\\*", "~*~");
    expression = expression.replaceAll("-", "~-~");
    expression = expression.replaceAll("/+", "~/~");
    expression = expression.replaceAll("\\(", "~(~"); //also you can use [(] instead of \\(
    expression = expression.replaceAll("\\)", "~)~"); //also you can use [)] instead of \\)
    expression = expression.replaceAll("~~", "~");
    if(expression.startsWith("~")) {
        expression = expression.substring(1);
    }

    String[] expressionArray = expression.split("~");
    System.out.println(Arrays.toString(expressionArray));

public static String[] split(CharSequence input, String pattern) {
    return split(input, Pattern.compile(pattern));
}

public static String[] split(CharSequence input, Pattern pattern) {
    Matcher matcher = pattern.matcher(input);
    int start = 0;
    List<String> result = new ArrayList<>();
    while (matcher.find()) {
        result.add(input.subSequence(start, matcher.start()).toString());
        result.add(matcher.group());
        start = matcher.end();
    }
    if (start != input.length()) result.add(input.subSequence(start, input.length()).toString());
    return result.toArray(new String[0]);
}

@Test
public void splitsVariableLengthPattern() {
    String[] result = Split.split("/foo/$bar/bas", "\\$\\w+");
    Assert.assertArrayEquals(new String[] { "/foo/", "$bar", "/bas" }, result);
}

@Test
public void splitsEndingWithPattern() {
    String[] result = Split.split("/foo/$bar", "\\$\\w+");
    Assert.assertArrayEquals(new String[] { "/foo/", "$bar" }, result);
}

@Test
public void splitsStartingWithPattern() {
    String[] result = Split.split("$foo/bar", "\\$\\w+");
    Assert.assertArrayEquals(new String[] { "", "$foo", "/bar" }, result);
}

@Test
public void splitsNoMatchesPattern() {
    String[] result = Split.split("/foo/bar", "\\$\\w+");
    Assert.assertArrayEquals(new String[] { "/foo/bar" }, result);
}

package javaapplication2;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class JavaApplication2 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        String num = "58.5+variable-+98*78/96+a/78.7-3443*12-3";

        // Terrifying regex:
        //  (a)|(b)|(c) match a or b or c
        // where
        //   (a) is one or more digits optionally followed by a decimal point
        //       followed by one or more digits: (\d+(\.\d+)?)
        //   (b) is one of the set + * / - occurring once: ([+*/-])
        //   (c) is a sequence of one or more lowercase latin letter: ([a-z]+)
        Pattern tokenPattern = Pattern.compile("(\\d+(\\.\\d+)?)|([+*/-])|([a-z]+)");
        Matcher tokenMatcher = tokenPattern.matcher(num);

        List<String> tokens = new ArrayList<>();

        while (!tokenMatcher.hitEnd()) {
            if (tokenMatcher.find()) {
                tokens.add(tokenMatcher.group());
            } else {
                // report error
                break;
            }
        }

        System.out.println(tokens);
    }
}

[58.5, +, variable, -, +, 98, *, 78, /, 96, +, a, /, 78.7, -, 3443, *, 12, -, 3]

            String tokenRegex = /[\p{L}\p{N}]+/ // a String in Groovy, Unicode alphanumeric
            def finder = phraseForTokenising =~ tokenRegex
            // NB in Groovy the variable 'finder' is then of class java.util.regex.Matcher
            def finderIt = finder.iterator() // extra method added to Matcher by Groovy magic
            int start = 0
            boolean leadingDelim, trailingDelim
            def combinedTokensAndDelims = [] // create an array in Groovy

            while( finderIt.hasNext() )
            {
                def token = finderIt.next()
                int finderStart = finder.start()
                String delim = phraseForTokenising[ start  .. finderStart - 1 ]
                // Groovy: above gets slice of String/array
                if( start == 0 ) leadingDelim = finderStart != 0
                if( start > 0 || leadingDelim ) combinedTokensAndDelims << delim
                combinedTokensAndDelims << token // add element to end of array
                start = finder.end()
            }
            // start == 0 indicates no tokens found
            if( start > 0 ) {
                // finish by seeing whether there is a trailing delim
                trailingDelim = start < phraseForTokenising.length()
                if( trailingDelim ) combinedTokensAndDelims << phraseForTokenising[ start .. -1 ]

                println( "leading delim? $leadingDelim, trailing delim? $trailingDelim, combined array:\n $combinedTokensAndDelims" )

            }