issue #39 添加oauth2的支持

weixin-java-common/src/main/java/me/chanjar/weixin/common/api/WxConsts.java

@@ -128,4 +128,12 @@ public class WxConsts {
   /** 弹出地理位置选择器 */
   public static final String LOCATION_SELECT = "location_select";
 
+  ///////////////////////
+  // oauth2网页授权的scope
+  ///////////////////////
+  /** 不弹出授权页面，直接跳转，只能获取用户openid */
+  public static final String OAUTH2_SCOPE_BASE = "snsapi_base";
+  /** 弹出授权页面，可通过openid拿到昵称、性别、所在地。并且，即使在未关注的情况下，只要用户授权，也能获取其信息 */
+  public static final String OAUTH2_SCOPE_USER_INFO = "snsapi_userinfo";
+
 }

weixin-java-common/src/main/java/me/chanjar/weixin/common/util/http/URIUtil.java

@@ -0,0 +1,47 @@
+package me.chanjar.weixin.common.util.http;
+
+import me.chanjar.weixin.common.util.StringUtils;
+
+import java.io.UnsupportedEncodingException;
+
+public class URIUtil {
+
+  private static final String ALLOWED_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.!~*'()";
+
+  public static String encodeURIComponent(String input) {
+    if (StringUtils.isEmpty(input)) {
+      return input;
+    }
+
+    int l = input.length();
+    StringBuilder o = new StringBuilder(l * 3);
+    try {
+      for (int i = 0; i < l; i++) {
+        String e = input.substring(i, i + 1);
+        if (ALLOWED_CHARS.indexOf(e) == -1) {
+          byte[] b = e.getBytes("utf-8");
+          o.append(getHex(b));
+          continue;
+        }
+        o.append(e);
+      }
+      return o.toString();
+    } catch (UnsupportedEncodingException e) {
+      e.printStackTrace();
+    }
+    return input;
+  }
+
+  private static String getHex(byte buf[]) {
+    StringBuilder o = new StringBuilder(buf.length * 3);
+    for (int i = 0; i < buf.length; i++) {
+      int n = (int) buf[i] & 0xff;
+      o.append("%");
+      if (n < 0x10) {
+        o.append("0");
+      }
+      o.append(Long.toString(n, 16).toUpperCase());
+    }
+    return o.toString();
+  }
+}