issue-4785: Check uniformed with all actual tables' meta data in once when loading them (#4826)

* issue-4785: Check uniformed with all actual tables' meta data in once when loading them.

* issue-4785: Add Object for holding error meta data while checking uniformed table meta data configuration.

* issue-4785: Move the new class as inner class; extract private method and rename some variables.

* issue-4785: Add final for class and its fields; remove inner class accessLevel, etc.

* issue-4785: Add final for class and its fields; remove inner class accessLevel, etc.

* issue-4785: A few more better readable optimizations.

* issue-4785: Optimize exception details.

* issue-4785: Remove unnecessary local variable.

* issue-4785: Remove an unnecessary append operation for initializing error message.

sharding-core/sharding-core-common/src/main/java/org/apache/shardingsphere/core/metadata/ShardingMetaDataLoader.java

@@ -17,6 +17,7 @@
 
 package org.apache.shardingsphere.core.metadata;
 
+import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.shardingsphere.core.rule.DataNode;
@@ -30,10 +31,12 @@ import org.apache.shardingsphere.underlying.common.exception.ShardingSphereExcep
 
 import javax.sql.DataSource;
 import java.sql.SQLException;
-import java.util.Collections;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
+import java.util.List;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.Collections;
 import java.util.Map.Entry;
 import java.util.Optional;
 
@@ -43,7 +46,9 @@ import java.util.Optional;
 @RequiredArgsConstructor
 @Slf4j(topic = "ShardingSphere-metadata")
 public final class ShardingMetaDataLoader {
-    
+
+    private static final String LINE_SEPARATOR = System.getProperty("line.separator");
+
     private final Map<String, DataSource> dataSourceMap;
     
     private final ShardingRule shardingRule;
@@ -103,17 +108,36 @@ public final class ShardingMetaDataLoader {
         return actualDefaultDataSourceName.isPresent()
                 ? SchemaMetaDataLoader.load(dataSourceMap.get(actualDefaultDataSourceName.get()), maxConnectionsSizePerQuery) : new SchemaMetaData(Collections.emptyMap());
     }
-    
-    // TODO check all meta data in once
+
     private void checkUniformed(final String logicTableName, final Map<String, TableMetaData> actualTableMetaDataMap) {
         ShardingTableMetaDataDecorator decorator = new ShardingTableMetaDataDecorator();
         TableMetaData sample = decorator.decorate(actualTableMetaDataMap.values().iterator().next(), logicTableName, shardingRule);
+        Collection<TableMetaDataViolation> violations = new LinkedList<>();
         for (Entry<String, TableMetaData> entry : actualTableMetaDataMap.entrySet()) {
             if (!sample.equals(decorator.decorate(entry.getValue(), logicTableName, shardingRule))) {
-                throw new ShardingSphereException(
-                        "Cannot get uniformed table structure for logic table `%s` and actual table `%s`. The different meta data of actual tables are as follows:\n%s\n%s.",
-                        logicTableName, entry.getKey(), sample, entry.getValue());
+                violations.add(new TableMetaDataViolation(entry.getKey(), entry.getValue()));
             }
         }
+        throwExceptionIfNecessary(violations, logicTableName);
+    }
+
+    private void throwExceptionIfNecessary(final Collection<TableMetaDataViolation> violations, final String logicTableName) {
+        if (!violations.isEmpty()) {
+            StringBuilder errorMessage = new StringBuilder(
+                "Cannot get uniformed table structure for logic table `%s`, it has different meta data of actual tables are as follows:").append(LINE_SEPARATOR);
+            for (TableMetaDataViolation each : violations) {
+                errorMessage.append("actual table: ").append(each.getActualTableName()).append(", meta data: ").append(each.getTableMetaData()).append(LINE_SEPARATOR);
+            }
+            throw new ShardingSphereException(errorMessage.toString(), logicTableName);
+        }
+    }
+
+    @RequiredArgsConstructor
+    @Getter
+    private final class TableMetaDataViolation {
+
+        private final String actualTableName;
+
+        private final TableMetaData tableMetaData;
     }
 }