There are times you want to define a custom data type in Hibernate. Here is an example of using a custom ImageType defined as a Blob databse type to store images, excel files, etc.
Step 1: Define the custom Hibernate data type “ImageTpe” as shown below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 | package com.myapp.common; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.Serializable; import java.sql.Blob; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Types; import java.util.Arrays; import org.hibernate.HibernateException; import org.hibernate.engine.spi.SessionImplementor; import org.hibernate.usertype.UserType; public class ImageType implements UserType { @Override public int[] sqlTypes() { return new int[] {Types.BLOB }; } @Override public Class<Blob> returnedClass() { return Blob.class; } @Override public Object nullSafeGet(ResultSet rs, String[] names, SessionImplementor session, Object owner) throws HibernateException, SQLException { return getBlobFromBinaryStream(rs, names[0]); } private byte[] getBlobFromBinaryStream(ResultSet rs, String aColName) throws SQLException { byte[] theBuff = new byte[2 * 1024]; InputStream theInStream = rs.getBinaryStream(aColName); ByteArrayOutputStream theBaos = new ByteArrayOutputStream(); int n = 0; try { if (theInStream != null) { while (-1 != (n = theInStream.read(theBuff))) { theBaos.write(theBuff, 0, n); } } theBaos.flush(); } catch (IOException e) { e.printStackTrace(); } return theBaos.toByteArray(); } @Override public void nullSafeSet(PreparedStatement stmt, Object aValue, int aIndex, SessionImplementor session) throws HibernateException, SQLException { stmt.setBytes(aIndex, (byte[]) aValue); } @Override public boolean equals(Object obj, Object other) { if ((obj == other) || (obj != null && other != null && Arraothers.equals( ((byte[]) obj), ((byte[]) other)))) { return true; } return false; } @Override public int hashCode(Object obj) throws HibernateException { return obj.hashCode(); } @Override public boolean isMutable() { return false; } @Override public Object assemble(Serializable aSerializableObject, Object obj) throws HibernateException { return null; } @Override public Serializable disassemble(Object onj) throws HibernateException { return null; } @Override public Object replace(Object obj1, obj2, Object obj3) throws HibernateException { return null; } @Override public Object deepCopy(Object obj) { return obj; } } |
Step 2: Use the custom data type as shown below in Hibernate entity.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 | package com.myapp.model.images; import java.util.Date; import javax.persistence.AttributeOverride; import javax.persistence.AttributeOverrides; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.EnumType; import javax.persistence.Enumerated; import javax.persistence.NamedQueries; import javax.persistence.NamedQuery; import javax.persistence.Table; import org.hibernate.annotations.SQLDelete; import org.hibernate.annotations.Type; import org.hibernate.annotations.Where; @Entity @Table(name = "images", schema = "dbo", catalog = "my_catalog") @Where(clause = "inactiveFlag = 'N'") @SQLDelete(sql = "UPDATE MyImages SET inactiveFlag = 'Y' WHERE MyImagesID = ? and timestamp = ?") public class MyImages { private static final long serialVersionUID = 1L; public enum Status { PENDINDING_RELEASE, RELEASED; } private String name; private byte[] image = new byte[0]; private Status status; private byte[] timestamp; public MyImages() { } @Column(name = "name", nullable = false, length = 100) public String getName() { return name; } public void setName(String name) { this.name = name; } //custom type @Type(type = "com.myapp.common.ImageType") @Column(name = "rules", nullable = false) public byte[] getImage() { return image; } public void setImage(byte[] image) { this.image = image; } @Enumerated(EnumType.STRING) @Column(name = "Status", nullable = false, length = 30) public Status getStatus() { return status; } public void setStatus(Status status) { this.status = status; } @Version @Column(name = "Timestamp", insertable = false, updatable = false, unique = true, nullable = false) @Generated(GenerationTime.ALWAYS) public byte[] getTimestamp() { return timestamp; } public void setTimestamp(byte[] timestamp) { this.timestamp = timestamp; } } |
