http://java.dzone.com/articles/two-ways-convert-java-map
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
public class MapUtil {
public static String mapToString(Map<String, String> map) {
StringBuilder stringBuilder = new StringBuilder();
for (String key : map.keySet()) {
if (stringBuilder.length() > 0) {
stringBuilder.append("&");
}
String value = map.get(key);
try {
stringBuilder.append((key != null ? URLEncoder.encode(key, "UTF-8") : ""));
stringBuilder.append("=");
stringBuilder.append(value != null ? URLEncoder.encode(value, "UTF-8") : "");
} catch (UnsupportedEncodingException e) {
throw new RuntimeException("This method requires UTF-8 encoding support", e);
}
}
return stringBuilder.toString();
}
public static Map<String, String> stringToMap(String input) {
Map<String, String> map = new HashMap<String, String>();
String[] nameValuePairs = input.split("&");
for (String nameValuePair : nameValuePairs) {
String[] nameValue = nameValuePair.split("=");
try {
map.put(URLDecoder.decode(nameValue[0], "UTF-8"), nameValue.length > 1 ? URLDecoder.decode(
nameValue[1], "UTF-8") : "");
} catch (UnsupportedEncodingException e) {
throw new RuntimeException("This method requires UTF-8 encoding support", e);
}
}
return map;
}
}
Example usage
Map<String, String> map = new HashMap<String, String>();
map.put("color", "red");
map.put("symbols", "{,=&*?}");
map.put("empty", "");
String output = MapUtil.mapToString(map);
Map<String, String> parsedMap = MapUtil.stringToMap(output);
for (String key : map.keySet()) {
Assert.assertEquals(parsedMap.get(key), map.get(key));
}
map.put("color", "red");
map.put("symbols", "{,=&*?}");
map.put("empty", "");
String output = MapUtil.mapToString(map);
Map<String, String> parsedMap = MapUtil.stringToMap(output);
for (String key : map.keySet()) {
Assert.assertEquals(parsedMap.get(key), map.get(key));
}
symbols=%7B%2C%3D%26*%3F%7D&color=red∅=java.lang.ClassCastException: [Ljava.lang.String; cannot be cast to java.lang.String
