看到所有的答案，我认为没有人提到比在java的新版本，你可以这样做:

String s = """
    This
    is 
    a
    multiline
    string
    """;
System.out.println(s);

这是它打印的内容:

This
is
a
multiline
string

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。

这是你不应该在不考虑它在做什么的情况下使用的东西。但对于一次性脚本，我已经成功地使用了这个方法:

例子:

    System.out.println(S(/*
This is a CRAZY " ' ' " multiline string with all sorts of strange 
   characters!
*/));

代码:

// From: http://blog.efftinge.de/2008/10/multi-line-string-literals-in-java.html
// Takes a comment (/**/) and turns everything inside the comment to a string that is returned from S()
public static String S() {
    StackTraceElement element = new RuntimeException().getStackTrace()[1];
    String name = element.getClassName().replace('.', '/') + ".java";
    StringBuilder sb = new StringBuilder();
    String line = null;
    InputStream in = classLoader.getResourceAsStream(name);
    String s = convertStreamToString(in, element.getLineNumber());
    return s.substring(s.indexOf("/*")+2, s.indexOf("*/"));
}

// From http://www.kodejava.org/examples/266.html
private static String convertStreamToString(InputStream is, int lineNum) {
    /*
     * To convert the InputStream to String we use the BufferedReader.readLine()
     * method. We iterate until the BufferedReader return null which means
     * there's no more data to read. Each line will appended to a StringBuilder
     * and returned as String.
     */
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();

    String line = null; int i = 1;
    try {
        while ((line = reader.readLine()) != null) {
            if (i++ >= lineNum) {
                sb.append(line + "\n");
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    return sb.toString();
}

这个问题有两个答案:

In you want to stick to pure Java, with Java 14 being released in March 2020, you can leverage the JEP 368 - Text Blocks, in Second Preview mode. Actually the feature is in preview mode in other releases (at least 13 has it). I created and example set here. While this feature is useful, it can be easily abused. Remember that Java requires compilation - having large character arrays in your code can be an easy way to shoot yourself in the leg (if you want a quick change, you will need recompilation - that toolset might not be available to the guy operating your application).

根据我的经验，建议在配置文件中保留大字符串(通常是应用程序操作员可以/应该在运行时更改的字符串)。

总结:负责地使用文本块:)。

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。

Java 13预览:

Text Blocks Come to Java. Java 13 delivers long-awaited multiline string by Mala Gupta With text blocks, Java 13 is making it easier for you to work with multiline string literals. You no longer need to escape the special characters in string literals or use concatenation operators for values that span multiple lines. Text block is defined using three double quotes (""") as the opening and closing delimiters. The opening delimiter can be followed by zero or more white spaces and a line terminator.

例子:

 String s1 = """
 text
 text
 text
 """;