有时候,很多文本存入数据库或者文件中,某些变量或者模板中会存在占位符的情况,然而每次读取,一个个去字符串.replace去替换就很麻烦,于是写个占位符替换工具类
具体代码:
代码语言:javascript复制import java.util.HashMap;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 配置文件或模板中的占位符替换工具类
* Date: 15-5-8
* Time: 下午4:12
*/
public class PlaceholderUtils {
private static final Logger logger = LoggerFactory.getLogger(PlaceholderUtils.class);
/**
* Prefix for system property placeholders: "${"
*/
public static final String PLACEHOLDER_PREFIX = "${";
/**
* Suffix for system property placeholders: "}"
*/
public static final String PLACEHOLDER_SUFFIX = "}";
public static String resolvePlaceholders(String text, Map<String, String> parameter) {
if (parameter == null || parameter.isEmpty()) {
return text;
}
StringBuffer buf = new StringBuffer(text);
int startIndex = buf.indexOf(PLACEHOLDER_PREFIX);
while (startIndex != -1) {
int endIndex = buf.indexOf(PLACEHOLDER_SUFFIX, startIndex PLACEHOLDER_PREFIX.length());
if (endIndex != -1) {
String placeholder = buf.substring(startIndex PLACEHOLDER_PREFIX.length(), endIndex);
int nextIndex = endIndex PLACEHOLDER_SUFFIX.length();
try {
String propVal = parameter.get(placeholder);
if (propVal != null) {
buf.replace(startIndex, endIndex PLACEHOLDER_SUFFIX.length(), propVal);
nextIndex = startIndex propVal.length();
} else {
logger.warn("Could not resolve placeholder '" placeholder "' in [" text "] ");
}
} catch (Exception ex) {
logger.warn("Could not resolve placeholder '" placeholder "' in [" text "]: " ex);
}
startIndex = buf.indexOf(PLACEHOLDER_PREFIX, nextIndex);
} else {
startIndex = -1;
}
}
return buf.toString();
}
public static void main(String[] args) {
String aa= "我们都是好孩子,${num}说是嘛? 我觉得${people}是傻蛋!";
Map<String, String> map = new HashMap<String, String>();
map.put("num","小二比");
map.put("people","小明");
System.out.println(PlaceholderUtils.resolvePlaceholders(aa, map));
}
}
输出结果:
我们都是好孩子,小二比说是嘛? 我觉得小明是傻蛋