问题:

So I essentially need to do this:

String text = "line1\n"; text += "line2\n"; text += "line3\n"; useString( text );

There is more involved, but that's the basic idea. Is there anything out there that might let me do something more along the lines of this though?

DesiredStringThinger text = new DesiredStringThinger(); text.append( "line1" ); text.append( "line2" ); text.append( "line3" ); useString( text.toString() );

Obviously, it does not need to work exactly like that, but I think I get the basic point across. There is always the option of writing a loop which processes the text myself, but it would be nice if there is a standard Java class out there that already does something like this rather than me needing to carry a class around between applications just so I can do something so trivial.

Thanks!

回答1:

You can use a StringWriter wrapped in a PrintWriter:

StringWriter stringWriter = new StringWriter(); PrintWriter writer = new PrintWriter(stringWriter, true); writer.println("line1"); writer.println("line2"); writer.println("line3"); useString(stringWriter.toString());

回答2:

AFAIK there's no library class that allows you to do so.

The following does the work though:

class DesiredStringThinger {   StringBuilder text = new StringBuilder();    public void append(String s) { text.append(s).append("\n"); }    @Override   public String toString() { return text.toString(); } }

回答3:

public String createString () {    StringBuilder sb = new StringBuilder ();    String txt = appendLine("firstline", sb).appendLine("2ndLine", sb).toString(); }  private StringBuilder appendLine (String line, StringBuilder sb) {    String lsp = System.getProperty("line.separator");    return sb.append (line).append (lsp); }

回答4:

You can use from Apache Commons the StringUtils.join helper. Which allows to build a String from a list. You can add the 'delimiter' character/string.

回答5:

If you are willing to use external libraries, check out the Joiner in Guava.

Your code would go to something like

String result = Joiner.on("\n").join(parts);

where parts is an Iterable<String>.

回答6:

You can use a StringBuffer

StringBuffer text = new StringBuffer(); text.append("line1");   text.append("line2");   ...   useString(text.toString());

This will not append the new line character, but you can certainly append that as well for each line.

回答7:

Perhaps the lowest impact method is to add a static method to append with a new line to a StringBuilder.

 public static StringBuilder appendln(StringBuilder buff, String str) {      return buff.append(str).append('\n');  }

But @Joachim Sauer beats me to my preferred solution. For more complex examples you might want to use your own Writer decorator, as @Rahul G (only use private fields).

回答8:

If you are not crazy about performance, I think this is clean and neat.

class DesiredStringThinger {   StringBuilder sb = new StringBuilder();    public void concat(String... s) {        for(String str : s){          sb.append(s).append("\n");       }   }    @Override   public String toString() {        return sb.toString();   } }

转载请标明出处:Is there an easy way to concatenate several lines of text into a string without constantly appending a newline?

文章来源: Is there an easy way to concatenate several lines of text into a string without constantly appending a newline?

标签

string

stringbuilder