我知道这是一个老问题，但是对于感兴趣的开发人员来说，多行文字将在#Java12中

http://mail.openjdk.java.net/pipermail/amber-dev/2018-July/003254.html

一个简单的选择是使用SciTE (http://www.scintilla.org/SciTEDownload.html)这样的编辑器编辑java代码，它允许您对文本进行WRAP，以便容易地查看和编辑长字符串。如果你需要转义字符，你只需输入它们。通过关闭“换行”选项，您可以检查字符串是否仍然是一个很长的单行字符串。当然，如果不是，编译器也会告诉你。

Eclipse或NetBeans是否支持编辑器中的文本包装，我不知道，因为它们有太多的选项。但如果没有，这将是一个很好的补充。

如果你像我一样喜欢谷歌的番石榴，它可以提供一个相当干净的表示和一个很好的，简单的方法来不硬编码你的换行符:

String out = Joiner.on(newline).join(ImmutableList.of(
    "line1",
    "line2",
    "line3"));

我有时使用一个并行groovy类来充当一个字符串包

这里的java类

public class Test {
    public static void main(String[] args) {
        System.out.println(TestStrings.json1);
        // consume .. parse json
    }
}

以及TestStrings.groovy中令人垂涎的多行字符串

class TestStrings {
    public static String json1 = """
    {
        "name": "Fakeer's Json",
        "age":100,
        "messages":["msg 1","msg 2","msg 3"]
    }""";
}

当然，这只适用于静态字符串。如果我必须在文本中插入变量，我会将整个文件更改为groovy。只要保持强类型实践，它就可以实现。

注意:这个答案适用于Java 14及以上版本。

Java 15引入了文本块(多行文字)。详情请看这个答案。

听起来像是要做一个多行文字，这在Java中是不存在的。

你最好的选择是用+ d组合的字符串。人们提到的一些其他选项(StringBuilder, String。format, String.join)只有当你从一个字符串数组开始时才更可取。

考虑一下:

String s = "It was the best of times, it was the worst of times,\n"
         + "it was the age of wisdom, it was the age of foolishness,\n"
         + "it was the epoch of belief, it was the epoch of incredulity,\n"
         + "it was the season of Light, it was the season of Darkness,\n"
         + "it was the spring of hope, it was the winter of despair,\n"
         + "we had everything before us, we had nothing before us";

与StringBuilder:

String s = new StringBuilder()
           .append("It was the best of times, it was the worst of times,\n")
           .append("it was the age of wisdom, it was the age of foolishness,\n")
           .append("it was the epoch of belief, it was the epoch of incredulity,\n")
           .append("it was the season of Light, it was the season of Darkness,\n")
           .append("it was the spring of hope, it was the winter of despair,\n")
           .append("we had everything before us, we had nothing before us")
           .toString();

与String.format ():

String s = String.format("%s\n%s\n%s\n%s\n%s\n%s"
         , "It was the best of times, it was the worst of times,"
         , "it was the age of wisdom, it was the age of foolishness,"
         , "it was the epoch of belief, it was the epoch of incredulity,"
         , "it was the season of Light, it was the season of Darkness,"
         , "it was the spring of hope, it was the winter of despair,"
         , "we had everything before us, we had nothing before us"
);

相对于Java8 String.join():

String s = String.join("\n"
         , "It was the best of times, it was the worst of times,"
         , "it was the age of wisdom, it was the age of foolishness,"
         , "it was the epoch of belief, it was the epoch of incredulity,"
         , "it was the season of Light, it was the season of Darkness,"
         , "it was the spring of hope, it was the winter of despair,"
         , "we had everything before us, we had nothing before us"
);

如果您想在特定的系统中使用换行符，您要么需要使用system . lineseparator()，要么可以在String.format中使用%n。

另一种选择是将资源放在文本文件中，只读取该文件的内容。对于非常大的字符串，这将是可取的，以避免不必要地膨胀您的类文件。

后期模型JAVA对+和常量字符串进行了优化，在幕后使用了StringBuffer，所以你不想让它使你的代码变得混乱。

它指出了JAVA的一个疏忽，它不像ANSI C在双引号字符串之间只有空白的自动连接，例如:

const char usage = "\n"
"Usage: xxxx <options>\n"
"\n"
"Removes your options as designated by the required parameter <options>,\n"
"which must be one of the following strings:\n"
"  love\n"
"  sex\n"
"  drugs\n"
"  rockandroll\n"
"\n" ;

我想有一个多行字符数组常量，其中嵌入换行是光荣的，所以我可以在没有任何混乱的情况下呈现块，例如:

String Query = "
SELECT
    some_column,
    another column
  FROM
      one_table a
    JOIN
      another_table b
    ON    a.id = b.id
      AND a.role_code = b.role_code
  WHERE a.dept = 'sales'
    AND b.sales_quote > 1000
  Order BY 1, 2
" ;

要做到这一点，需要打败JAVA之神。