基于mybatis中test条件中单引号双引号的问题

<when  test=“channel ==null” >
<when  test='channel =="QT"' >

//CountryDao.java
public interface CountryDao {
    CountryDo getByType(@Param("type") String type);
}
//CountryManager.java
@Component("countryManager")
public class CountryManager {
    @Autowired
    private CountryDao countryDao;
    public CountryDo getByType(String type){
        return countryDao.getByType(type);
    }
}

//.xml
<select id="getByType" resultType="com.github.**.domain.CountryDo">
    <choose>
      //注意写法`type=='0'`
        <when test="type == '0'">
            SELECT * FROM country WHERE country_id = 2
        </when>
        <otherwise>
            SELECT * FROM country WHERE country_id = 3;
        </otherwise>
    </choose>
</select>

@Test
public void getByTypeTest() throws JsonProcessingException {
    String type = "0";
    CountryDo countryDo = countryManager.getByType(type);
    ObjectMapper mapper = new ObjectMapper();
    String json = mapper.writeValueAsString(countryDo);
    System.out.println(json);
}

<select id="getByType" resultType="com.github.sijing.domain.CountryDo">
    <choose>
        <when test="0 ==''">
            SELECT * FROM country WHERE country_id = 2
        </when>
        <otherwise>
            SELECT * FROM country WHERE country_id = 3;
        </otherwise>
    </choose>
</select>

@Test
public void getByTypeTest() throws JsonProcessingException {
    //此时传值已经没有影响了
    String type = "0";
    CountryDo countryDo = countryManager.getByType(type);
    ObjectMapper mapper = new ObjectMapper();
    String json = mapper.writeValueAsString(countryDo);
    System.out.println(json);
}

// IfSqlNode.
@Override
 public boolean apply(DynamicContext context) {
   if (evaluator.evaluateBoolean(test, context.getBindings())) {
     contents.apply(context);
     return true;
   }
   return false;
 }

//ExpressionEvaluator.java OGNL表达式处理
public boolean evaluateBoolean(String expression, Object parameterObject) {
  Object value = OgnlCache.getValue(expression, parameterObject);
  if (value instanceof Boolean) {
    return (Boolean) value;
  }
  if (value instanceof Number) {
    return new BigDecimal(String.valueOf(value)).compareTo(BigDecimal.ZERO) != 0;
  }
  return value != null;
}

case NONNUMERIC:
    if ((t1 == NONNUMERIC) && (t2 == NONNUMERIC)) {
        if ((v1 instanceof Comparable) && v1.getClass().isAssignableFrom(v2.getClass())) {
            result = ((Comparable) v1).compareTo(v2);
            break;
        } else {
            throw new IllegalArgumentException("invalid comparison: " + v1.getClass().getName() + " and "
                    + v2.getClass().getName());
        }
    }
    // else fall through
case FLOAT:
case DOUBLE:
    //v1=0, v2=""
    double dv1 = doubleValue(v1),
    dv2 = doubleValue(v2);
    return (dv1 == dv2) ? 0 : ((dv1 < dv2) ? -1 : 1);

public static double doubleValue(Object value)
        throws NumberFormatException
    {
        if (value == null) return 0.0;
        Class c = value.getClass();
        if (c.getSuperclass() == Number.class) return ((Number) value).doubleValue();
        if (c == Boolean.class) return ((Boolean) value).booleanValue() ? 1 : 0;
        if (c == Character.class) return ((Character) value).charValue();
        String s = stringValue(value, true);
        return (s.length() == 0) ? 0.0 : Double.parseDouble(s);
    }