小编use*_*316的帖子

我从.txt文件中读到了这个:

<?xml version="1.0"?>
<!DOCTYPE cross-domain-policy SYSTEM "/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
   <allow-access-from domain="*" to-ports="*" />
</cross-domain-policy>

但阅读之后再输出我得到这个:

null<?xml version="1.0"?>
<!DOCTYPE cross-domain-policy SYSTEM "/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
   <allow-access-from domain="*" to-ports="*" />
</cross-domain-policy>

在开头为null,这是方法:

public class Filer {

    private static String str;
    public static String read(String file) {

        BufferedReader br = null;
        try {

            String sCurrentLine;

            br = new BufferedReader(new FileReader(file));

            while ((sCurrentLine = br.readLine()) != null) {

                str += sCurrentLine;
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null)br.close(); …