WIP: Bind validation

ebean-api/src/main/java/io/ebean/DataBindException.java

@@ -0,0 +1,24 @@
+package io.ebean;
+
+import javax.persistence.PersistenceException;
+
+/**
+ * Thrown when a bind validator detects a data bind error.
+ */
+public class DataBindException extends PersistenceException {
+  private static final long serialVersionUID = -1755215106960660645L;
+
+  /**
+   * Create with a message.
+   */
+  public DataBindException(String message) {
+    super(message);
+  }
+
+  /**
+   * Create with a message and cause.
+   */
+  public DataBindException(String message, Throwable cause) {
+    super(message, cause);
+  }
+}

ebean-api/src/main/java/io/ebean/config/dbplatform/BasicBindValidatorFactory.java

@@ -0,0 +1,65 @@
+package io.ebean.config.dbplatform;
+
+import io.ebean.DataBindException;
+
+import java.io.File;
+import java.lang.reflect.Array;
+import java.sql.Types;
+
+/**
+ * @author Roland Praml, FOCONIS AG
+ */
+public class BasicBindValidatorFactory implements BindValidatorFactory {
+
+  protected boolean isLengthBased(int jdbcType) {
+    switch (jdbcType) {
+      case Types.BLOB:
+      case Types.CLOB:
+      case Types.LONGVARBINARY:
+      case Types.LONGVARCHAR:
+      case Types.VARBINARY:
+      case Types.BINARY:
+      case Types.CHAR:
+      case Types.VARCHAR:
+      case Types.NCHAR:
+      case Types.NVARCHAR:
+      case Types.NCLOB:
+      case Types.LONGNVARCHAR:
+      case Types.SQLXML:
+      case ExtraDbTypes.JSON:
+      case ExtraDbTypes.JSONB:
+      case ExtraDbTypes.JSONClob:
+      case ExtraDbTypes.JSONBlob:
+      case ExtraDbTypes.JSONVarchar:
+        return true;
+      default:
+        return false;
+    }
+  }
+
+  @Override
+  public BindValidator create(PropertyDefinition property) {
+    if (property.getDbLength() > 0 && isLengthBased(property.getJdbcType())) {
+      return value -> validate(value, property.getDbLength(), property.getTable(), property.getColumn());
+    } else {
+      return null;
+    }
+  }
+
+  /**
+   * Default validator, that handles length check for String, Arrays, and Files
+   */
+  protected void validate(Object value, int dbLength, String table, String column) {
+    int valueLength = 0;
+    if (value instanceof String) {
+      valueLength = ((String) value).length();
+    } else if (value instanceof File) {
+      valueLength = (int) ((File) value).length();
+    } else if (value != null && value.getClass().isArray()) {
+      valueLength = Array.getLength(value);
+    }
+    if (valueLength > dbLength) {
+      throw new DataBindException("Value of length " + valueLength + " exceeds limit of " + dbLength + " for " + table + "." + column);
+    }
+  }
+}

ebean-api/src/main/java/io/ebean/config/dbplatform/BindValidator.java

@@ -0,0 +1,17 @@
+package io.ebean.config.dbplatform;
+
+import io.ebean.DataBindException;
+
+/**
+ * Validates a value at bind level. See BindValidatorFactory for details.
+ *
+ * @author Roland Praml, FOCONIS AG
+ */
+@FunctionalInterface
+public interface BindValidator {
+  /**
+   * The validate method should throw a DataBindException, if the value is invalid.
+   */
+  void validate(Object value) throws DataBindException;
+
+}

ebean-api/src/main/java/io/ebean/config/dbplatform/BindValidatorFactory.java

@@ -0,0 +1,21 @@
+package io.ebean.config.dbplatform;
+
+/**
+ * The database platforms treat values that will exceed length or precision differently.
+ * Some will silently truncate varchars, if they are too long. This is fatal, when saving JSONs,
+ * because the JSON mostly breaks by this truncation.
+ * <p>
+ * BindValidators can be implemented depending on the database platform needs.
+ * E.g. they can perform length checks of varchars/blobs/clobs/...
+ * It would be also possible to implement precision and range checks for timestamps or numeric values.
+ * or 'confidental checks' - e.g. detect if all password hashes are SHA256
+ *
+ * @author Roland Praml, FOCONIS AG
+ */
+@FunctionalInterface
+public interface BindValidatorFactory {
+  /**
+   * Creates a bindValidator. The <code>propertyDefinition</code> provides information like JDBC-type or DbLength.
+   */
+  BindValidator create(PropertyDefinition propertyDefinition);
+}

ebean-api/src/main/java/io/ebean/config/dbplatform/DatabasePlatform.java

@@ -197,6 +197,8 @@ public class DatabasePlatform {
 
   protected boolean supportsNativeIlike;
 
+  protected BindValidatorFactory bindValidatorFactory = new BasicBindValidatorFactory();
+
   protected SqlExceptionTranslator exceptionTranslator = new SqlCodeTranslator();
 
   /**
@@ -301,6 +303,17 @@ public boolean supportsNativeIlike() {
     return supportsNativeIlike;
   }
 
+  /**
+   * Return the bindValidatorFactory for this platform.
+   */
+  public BindValidatorFactory getBindValidatorFactory() {
+    return bindValidatorFactory;
+  }
+
+  public void setBindValidatorFactory(BindValidatorFactory bindValidatorFactory) {
+    this.bindValidatorFactory = bindValidatorFactory;
+  }
+
   /**
    * Return true if the platform supports delete statements with table alias.
    */

ebean-api/src/main/java/io/ebean/config/dbplatform/DbPlatformType.java

@@ -139,9 +139,7 @@ public String renderType(int deployLength, int deployScale, boolean strict) {
   protected void renderLengthScale(int deployLength, int deployScale, StringBuilder sb) {
     // see if there is a precision/scale to add (or not)
     int len = deployLength != 0 ? deployLength : defaultLength;
-    if (len == Integer.MAX_VALUE) {
-      sb.append("(max)"); // TODO: this is sqlserver specific
-    } else if (len > 0) {
+    if (len > 0) {
       sb.append("(");
       sb.append(len);
       int scale = deployScale != 0 ? deployScale : defaultScale;

ebean-api/src/main/java/io/ebean/config/dbplatform/DbPlatformTypeMapping.java

@@ -134,7 +134,7 @@ private void loadDefaults(boolean logicalTypes) {
   /**
    * Lookup the platform specific DbType given the standard sql type name.
    */
-  public DbPlatformType lookup(String name, boolean withScale) {
+  public DbPlatformType lookup(String name, int scale) {
     DbType type = lookup.byName(name);
     if (type == null) {
       throw new IllegalArgumentException("Unknown type [" + name + "] - not standard sql type");
@@ -148,19 +148,19 @@ public DbPlatformType lookup(String name, boolean withScale) {
       case JSONVARCHAR:
         return get(DbType.VARCHAR);
       case JSON:
-        return getJsonType(DbType.JSON, withScale);
+        return getJsonType(DbType.JSON, scale);
       case JSONB:
-        return getJsonType(DbType.JSONB, withScale);
+        return getJsonType(DbType.JSONB, scale);
       default:
         return get(type);
     }
   }
 
-  private DbPlatformType getJsonType(DbType type, boolean withScale) {
+  private DbPlatformType getJsonType(DbType type, int scale) {
     DbPlatformType dbType = get(type);
     if (dbType == JSON_CLOB_PLACEHOLDER) {
       // if we have scale that implies this maps to varchar
-      return withScale ? get(DbType.VARCHAR) : get(DbType.CLOB);
+      return scale <= 8000 && scale != 0 ? get(DbType.VARCHAR) : get(DbType.CLOB);
     }
     if (dbType == JSON_BLOB_PLACEHOLDER) {
       return get(DbType.BLOB);

ebean-api/src/main/java/io/ebean/config/dbplatform/InputStreamInfo.java

@@ -0,0 +1,27 @@
+package io.ebean.config.dbplatform;
+
+import java.io.InputStream;
+
+/**
+ * InputStreamInfo for BindValidation.
+ *
+ * @author Roland Praml, FOCONIS AG
+ */
+public class InputStreamInfo {
+  private final InputStream stream;
+
+  private final long length;
+
+  public InputStreamInfo(InputStream stream, long length) {
+    this.stream = stream;
+    this.length = length;
+  }
+
+  public InputStream stream() {
+    return stream;
+  }
+
+  public long length() {
+    return length;
+  }
+}

ebean-api/src/main/java/io/ebean/config/dbplatform/PropertyDefinition.java

@@ -0,0 +1,42 @@
+package io.ebean.config.dbplatform;
+
+/**
+ * Information about the property, that should be bind-validated.l
+ *
+ * @author Roland Praml, FOCONIS AG
+ */
+public class PropertyDefinition {
+  private final int jdbcType;
+  private final int dbLength;
+  private final String table;
+  private final String column;
+  private final String columnDefn;
+
+  public PropertyDefinition(int jdbcType, int dbLength, String baseTable, String column, String columnDefn) {
+    this.jdbcType = jdbcType;
+    this.dbLength = dbLength;
+    this.table = baseTable;
+    this.column = column;
+    this.columnDefn = columnDefn;
+  }
+
+  public int getJdbcType() {
+    return jdbcType;
+  }
+
+  public int getDbLength() {
+    return dbLength;
+  }
+
+  public String getTable() {
+    return table;
+  }
+
+  public String getColumn() {
+    return column;
+  }
+
+  public String getColumnDefn() {
+    return columnDefn;
+  }
+}

ebean-core-type/src/main/java/io/ebean/core/type/DataBinder.java

@@ -174,4 +174,9 @@ public interface DataBinder {
    */
   String popJson();
 
+  /**
+   * Returns the last bound object (e.g. for BindValidation)
+   */
+  Object popLastObject();
+
 }