使用String.concat而非StringBuilder,实测更快。

Author: Frodez

src/main/generator/mybatis/CustomXmlFormatter.java

@@ -40,14 +40,9 @@ private static class CustomXmlGenerator {
 		}
 
 		private static String generaterContent(Document document) {
-			StringBuilder sb = new StringBuilder();
-			sb.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
-			sb.append(lineSeparator);
-			sb.append(
-				"<!DOCTYPE mapper PUBLIC \"-//mybatis.org//DTD Mapper 3.0//EN\" \"http://mybatis.org/dtd/mybatis-3-mapper.dtd\">");
-			sb.append(lineSeparator);
-			sb.append(getFormattedContent(document.getRootElement(), 0));
-			return sb.toString();
+			return "<?xml version=\"1.0\" encoding=\"UTF-8\"?>".concat(lineSeparator).concat(
+				"<!DOCTYPE mapper PUBLIC \"-//mybatis.org//DTD Mapper 3.0//EN\" \"http://mybatis.org/dtd/mybatis-3-mapper.dtd\">")
+				.concat(lineSeparator).concat(getFormattedContent(document.getRootElement(), 0));
 		}
 
 		private static String getFormattedContent(XmlElement element, int indentLevel) {

src/main/java/frodez/config/aop/request/checker/impl/KeyGenerator.java

@@ -11,18 +11,18 @@
 public class KeyGenerator {
 
 	public static String servletKey(String sault, HttpServletRequest request) {
-		StringBuilder builder = new StringBuilder(sault).append(DefStr.SEPERATOR).append(request.getRequestURI());
+		String key = sault.concat(DefStr.SEPERATOR).concat(request.getRequestURI());
 		if (URLMatcher.needVerify(request.getRequestURI())) {
 			// 非登录接口使用token判断,同一token不能重复请求
 			String fullToken = TokenManager.getFullToken(request);
 			if (fullToken == null) {
-				return builder.toString();
+				return key;
 			} else {
-				return builder.append(DefStr.SEPERATOR).append(fullToken).toString();
+				return key.concat(DefStr.SEPERATOR).concat(fullToken);
 			}
 		} else {
 			// 登录接口使用IP判断,同一IP不能重复请求
-			return builder.append(DefStr.SEPERATOR).append(ServletUtil.getAddr(request)).toString();
+			return key.concat(DefStr.SEPERATOR).concat(ServletUtil.getAddr(request));
 		}
 	}
 

src/main/java/frodez/config/mvc/JacksonConfig.java

@@ -35,7 +35,6 @@
 import org.springframework.http.converter.json.MappingJacksonInputMessage;
 import org.springframework.http.converter.json.MappingJacksonValue;
 import org.springframework.lang.Nullable;
-import org.springframework.util.Assert;
 import org.springframework.util.TypeUtils;
 
 public class JsonHttpMessageConverer extends AbstractGenericHttpMessageConverter<Object> {
@@ -66,7 +65,6 @@ public JsonHttpMessageConverer(ObjectMapper objectMapper) {
 		DefaultPrettyPrinter prettyPrinter = new DefaultPrettyPrinter();
 		prettyPrinter.indentObjectsWith(new DefaultIndenter("  ", "\ndata:"));
 		this.ssePrettyPrinter = prettyPrinter;
-		setSupportedMediaTypes(Arrays.asList(MediaType.APPLICATION_JSON, new MediaType("application", "*+json")));
 	}
 
 	public JsonHttpMessageConverer(ObjectMapper objectMapper, MediaType supportedMediaType) {
@@ -94,29 +92,6 @@ private JavaType getJavaType(Type type, @Nullable Class<?> contextClass) {
 			.constructType(GenericTypeResolver.resolveType(type, contextClass)));
 	}
 
-	/**
-	 * Set the {@code ObjectMapper} for this view. If not set, a default {@link ObjectMapper#ObjectMapper()
-	 * ObjectMapper} is used.
-	 * <p>
-	 * Setting a custom-configured {@code ObjectMapper} is one way to take further control of the JSON serialization
-	 * process. For example, an extended {@link com.fasterxml.jackson.databind.ser.SerializerFactory} can be configured
-	 * that provides custom serializers for specific types. The other option for refining the serialization process is
-	 * to use Jackson's provided annotations on the types to be serialized, in which case a custom-configured
-	 * ObjectMapper is unnecessary.
-	 */
-	public void setObjectMapper(ObjectMapper objectMapper) {
-		Assert.notNull(objectMapper, "ObjectMapper must not be null");
-		this.objectMapper = objectMapper;
-		configurePrettyPrint();
-	}
-
-	/**
-	 * Return the underlying {@code ObjectMapper} for this view.
-	 */
-	public ObjectMapper getObjectMapper() {
-		return this.objectMapper;
-	}
-
 	/**
 	 * Whether to use the {@link DefaultPrettyPrinter} when writing JSON. This is a shortcut for setting up an
 	 * {@code ObjectMapper} as follows:

src/main/java/frodez/config/mvc/JsonHttpMessageConverer.java

@@ -3,6 +3,7 @@
 import frodez.util.json.JSONUtil;
 import java.util.List;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@@ -18,7 +19,8 @@ public void configureMessageConverters(List<HttpMessageConverter<?>> converters)
 				break;
 			}
 		}
-		converters.add(0, new JsonHttpMessageConverer(JSONUtil.mapper()));
+		converters.add(0, new JsonHttpMessageConverer(JSONUtil.mapper(), MediaType.APPLICATION_JSON, new MediaType(
+			"application", "*+json")));
 	}
 
 }

src/main/java/frodez/config/mvc/WebMvcConfiguration.java

@@ -30,8 +30,8 @@ public static boolean match(String regex, String input, int flag) {
 		if (flag == 0) {
 			return CACHE.computeIfAbsent(regex, i -> Pattern.compile(i)).matcher(input).matches();
 		}
-		return CACHE.computeIfAbsent(new StringBuilder(regex).append(DefStr.SEPERATOR).append(flag).toString(),
-			i -> Pattern.compile(i)).matcher(input).matches();
+		return CACHE.computeIfAbsent(regex.concat(DefStr.SEPERATOR).concat(Integer.toString(flag)), i -> Pattern
+			.compile(i)).matcher(input).matches();
 	}
 
 	/**

src/main/java/frodez/util/common/RegexUtil.java

@@ -38,8 +38,8 @@ public class BeanUtil {
 	private static final int GETTER_SETTER_MODIFIER = Modifier.PUBLIC;
 
 	private static BeanCopier getCopier(Object source, Object target) {
-		return COPIER_CACHE.computeIfAbsent(new StringBuilder(source.getClass().getName()).append(target.getClass()
-			.getName()).toString(), i -> BeanCopier.create(source.getClass(), target.getClass(), false));
+		return COPIER_CACHE.computeIfAbsent(source.getClass().getName().concat(target.getClass().getName()).toString(),
+			i -> BeanCopier.create(source.getClass(), target.getClass(), false));
 	}
 
 	/**
@@ -202,8 +202,8 @@ public Map<String, Pair<FastMethod, FastMethod>> getProperties(Class<?> klass) {
 					Pair<FastMethod, FastMethod> pair = new Pair<>();
 					pair.setKey(getter);
 					pair.setValue(method);
-					properties.put(new StringBuilder().append(Character.toLowerCase(propertyName.charAt(0))).append(
-						propertyName.substring(1)).toString(), pair);
+					properties.put(String.valueOf(Character.toLowerCase(propertyName.charAt(0))).concat(propertyName
+						.substring(1)), pair);
 				}
 			}
 		}

src/main/java/frodez/util/reflect/BeanUtil.java

@@ -0,0 +1,57 @@
+package frodez;
+
+import java.util.UUID;
+
+public class StringTest {
+
+	public static void main(String[] args) {
+		int testLength = 100000000;
+		int arrayLength = 10;
+		String[] arr = new String[arrayLength];
+
+		long start = System.currentTimeMillis();
+		String testStr = UUID.randomUUID().toString();
+		System.out.println("首次生成randomUUID耗时：" + (System.currentTimeMillis() - start));
+
+		//		start = new Date();
+		//		for (int i = 0; i < testLength; i++) {
+		//			testStr = UUID.randomUUID().toString();
+		//		}
+		//		System.out.println("非首次生成randomUUID " + testLength + "次耗时：" + (new Date().getTime() - start.getTime()));
+
+		@SuppressWarnings("unused")
+		String str = "";
+		start = System.currentTimeMillis();
+		for (int i = 0; i < testLength; i++) {
+			str = "";
+			for (int j = 0; j < arrayLength; j++) {
+				str = testStr + testStr;
+			}
+		}
+		System.out.println("String 拼接测试,测试长度" + testLength + ",测试字符串数组长度" + arr.length + ",完成时间" + (System
+			.currentTimeMillis() - start));
+
+		start = System.currentTimeMillis();
+		for (int i = 0; i < testLength; i++) {
+			str = "";
+			for (int j = 0; j < arrayLength; j++) {
+				str = testStr.concat(testStr);
+			}
+		}
+		System.out.println("String.concat 拼接测试,测试长度" + testLength + ",测试字符串数组长度" + arr.length + ",完成时间" + (System
+			.currentTimeMillis() - start));
+
+		start = System.currentTimeMillis();
+		for (int i = 0; i < testLength; i++) {
+			str = "";
+			StringBuilder sb = new StringBuilder();
+			for (int j = 0; j < arr.length; j++) {
+				sb.append(testStr);
+			}
+			str = sb.toString();
+		}
+		System.out.println("StringBuilder 拼接测试,测试长度" + testLength + ",测试字符串数组长度" + arr.length + ",完成时间" + (System
+			.currentTimeMillis() - start));
+	}
+
+}