【hive-部署】解决COMMENT中文乱码问题

1、查看及修改hive 元数据库字符集

#若元数据库的数据集不为latin1，执行下面语句修改修改
alter database hive character set latin1;

2、切换使用hive元数据库，修改以下表级别的字符集。
修改前：

修改：

#修改表字段注解和表注解
alter table COLUMNS_V2 modify column COMMENT varchar(256) character set utf8;
alter table TABLE_PARAMS modify column PARAM_VALUE varchar(4000) character set utf8;
#修改分区字段注解
alter table PARTITION_KEYS modify column PKEY_COMMENT varchar(4000) character set utf8;
alter table PARTITION_PARAMS modify column PARAM_VALUE varchar(4000) character set utf8;
#修改索引注解
alter table INDEX_PARAMS modify column PARAM_VALUE varchar(4000) character set utf8;

修改后：

image.png

3、修改 metastore 的连接 URL

      javax.jdo.option.ConnectionURL
      jdbc:mysql://hdc-data2:3306/hive_remote?createDatabaseIfNotExist=true&useUnicode=true&characterEncoding=UTF-8

重启hive和客户端

注意：做完此步发现原来创建表的comment还是中文不能正常显示，但新创建的表能正常显示。

4、解决原表的comment中文乱码(待续)

### Eclipse Workspace Patch 1.0
#P hive-0.12.0-jd-svn
Index: ql/src/java/org/apache/hadoop/hive/ql/metadata/formatting/MetaDataFormatUtils.java
===================================================================
--- ql/src/java/org/apache/hadoop/hive/ql/metadata/formatting/MetaDataFormatUtils.java  (revision 29)
+++ ql/src/java/org/apache/hadoop/hive/ql/metadata/formatting/MetaDataFormatUtils.java  (working copy)
@@ -28,6 +28,8 @@
 import java.util.Set;
 
 import org.apache.commons.lang.StringEscapeUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hive.conf.HiveConf;
 import org.apache.hadoop.hive.metastore.TableType;
 import org.apache.hadoop.hive.metastore.api.FieldSchema;
@@ -47,7 +49,7 @@
  *
  */
 public final class MetaDataFormatUtils {
-
+  private static final Log LOG = LogFactory.getLog("org.apache.hadoop.hive.ql.metadata.formatting.MetaDataFormatUtils");
   public static final String FIELD_DELIM = "\t";
   public static final String LINE_DELIM = "\n";
 
@@ -262,10 +264,20 @@
 
   private static void displayAllParameters(Map params, StringBuilder tableInfo) {
     List keys = new ArrayList(params.keySet());
+    String value = null;
     Collections.sort(keys);
     for (String key : keys) {
       tableInfo.append(FIELD_DELIM); // Ensures all params are indented.
-      formatOutput(key, StringEscapeUtils.escapeJava(params.get(key)), tableInfo);
+      value = params.get(key);
+      LOG.info(">>lvxin displayAllParameters:key="+key+";params.get(key)="+params.get(key));
+      if("comment".equals(key)&& null!=value && value.getBytes().length!=key.length())
+      {
+         formatOutput(key, value, tableInfo);
+      }
+      else
+      {
+         formatOutput(key, StringEscapeUtils.escapeJava(value), tableInfo);
+      }
     }
   }