记录一个很好用的占位符${}替换工具类

public class Parser {
    /**
     * 将字符串text中由openToken和closeToken组成的占位符依次替换为args数组中的值
     *
     * @param openToken
     * @param closeToken
     * @param text
     * @param args
     * @return
     */

    public static String parse(String openToken, String closeToken, String text, Object... args) {

        if (args == null || args.length <= 0) {

            return text;

        }

        int argsIndex = 0;

        if (text == null || text.isEmpty()) {

            return "";

        }

        char[] src = text.toCharArray();

        int offset = 0;

        // search open token

        int start = text.indexOf(openToken, offset);

        if (start == -1) {

            return text;

        }

        final StringBuilder builder = new StringBuilder();

        StringBuilder expression = null;

        while (start > -1) {

            if (start > 0 && src[start - 1] == '\\') {

                // this open token is escaped. remove the backslash and continue.

                builder.append(src, offset, start - offset - 1).append(openToken);

                offset = start + openToken.length();

            } else {

                // found open token. let's search close token.

                if (expression == null) {

                    expression = new StringBuilder();

                } else {

                    expression.setLength(0);

                }

                builder.append(src, offset, start - offset);

                offset = start + openToken.length();

                int end = text.indexOf(closeToken, offset);

                while (end > -1) {

                    if (end > offset && src[end - 1] == '\\') {

                        // this close token is escaped. remove the backslash and continue.

                        expression.append(src, offset, end - offset - 1).append(closeToken);

                        offset = end + closeToken.length();

                        end = text.indexOf(closeToken, offset);

                    } else {

                        expression.append(src, offset, end - offset);

                        offset = end + closeToken.length();

                        break;

                    }

                }

                if (end == -1) {

                    // close token was not found.

                    builder.append(src, start, src.length - start);

                    offset = src.length;

                } else {

                    ///仅仅修改了该else分支下的个别行代码

                    String value = (argsIndex <= args.length - 1) ?

                            (args[argsIndex] == null ? "" : args[argsIndex].toString()) : expression.toString();

                    builder.append(value);

                    offset = end + closeToken.length();

                    argsIndex++;


                }

            }

            start = text.indexOf(openToken, offset);

        }

        if (offset < src.length) {

            builder.append(src, offset, src.length - offset);

        }

        return builder.toString();

    }

    public static String parse0(String text, Object... args) {

        return Parser.parse("${", "}", text, args);

    }

    public static String parse1(String text, Object... args) {

        return Parser.parse("{", "}", text, args);

    }

    /**
     * 使用示例
     *
     * @param args
     */

    public static void main(String... args) {

        //{}被转义，不会被替换

        System.out.println(Parser.parse("{", "}", "我的名字是\\{},结果是{}，可信度是%{}", "雷锋", true, 100));

        System.out.println(Parser.parse0("我的名字是${name},结果是${}，可信度是${}%", "雷锋", true, 100));

        System.out.println(Parser.parse1("我的名字是{},结果是{}，可信度是%{}", "雷锋", true, 100));

//    输出结果如下：

//    我的名字是{},结果是true，可信度是%100

//    我的名字是雷锋,结果是true，可信度是%100

//    我的名字是雷锋,结果是true，可信度是%100

    }