java-samples/ZFileKSDS.java at master · zsystems/java-samples · GitHub

History

176 lines (152 loc) · 5.51 KB

Raw

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

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

* %Z%%W% %I%

* =========================================================================

* Licensed Materials - Property of IBM

* "Restricted Materials of IBM"

* DISCLAIMER:

* The following [enclosed] code is sample code created by IBM

* Corporation. This sample code is not part of any standard IBM product

* and is provided to you solely for the purpose of assisting you in the

* development of your applications. The code is provided 'AS IS',

* without warranty of any kind. IBM shall not be liable for any damages

* arising out of your use of the sample code, even if they have been

* advised of the possibility of such damages.

* =========================================================================

package com.ibm.jzos.sample;

import java.util.Arrays;

import com.ibm.jzos.ZFile;

import com.ibm.jzos.ZFileException;

/**

* Sample program that inserts, updates, locates, and deletes records in a VSAM

* KSDS using {@link ZFile}.

* <p>

* Refer to the C++ Programmer's guide for more information on processing VSAM

* files with the C library.

* This sample assumes that the //KSDS DD points to a VSAM cluster that

* was created something like this:

* <pre><code>

DEFINE CLUSTER -

(NAME(SOMENAME.CLUSTER) -

TRK(4 4) -

RECSZ(80 80) -

INDEXED -

NOREUSE -

KEYS(8 0) -

OWNER(YYYYYY) ) -

DATA -

(NAME(SOMENAME.KSDS.DA)) -

INDEX -

(NAME(SOMENAME.KSDS.IX))

</code></pre>

* @see com.ibm.jzos.ZFile

public class ZFileKSDS {

public static void main(String[] args) throws Exception {

String filename = "//DD:KSDS";

String options = "ab+,type=record";

int lrecl = 80;

int keyLen = 8;

ZFile zfile = new ZFile(filename, options);

try {

// construct some records with key prefixes

byte[] rec_1 = padToLength("AAAAAAAARecord 1", lrecl)

.getBytes(ZFile.DEFAULT_EBCDIC_CODE_PAGE);

byte[] rec_2 = padToLength("BBBBBBBBRecord 2", lrecl)

.getBytes(ZFile.DEFAULT_EBCDIC_CODE_PAGE);

byte[] rec_3 = padToLength("CCCCCCCCRecord 3", lrecl)

.getBytes(ZFile.DEFAULT_EBCDIC_CODE_PAGE);

byte[] recBuf = new byte[lrecl];

int nRead, nUpdated;

zfile.write(rec_1);

zfile.write(rec_2, 0, rec_2.length); // alternate form

zfile.write(rec_3);

// point to the first record

check("Found first record",

zfile.locate(rec_1, 0, keyLen, ZFile.LOCATE_KEY_EQ));

// read back the record and verify its contents

nRead = zfile.read(recBuf);

check("read len", lrecl == nRead);

check("rec_1 contents", Arrays.equals(rec_1, recBuf));

// update the record

byte[] rec_1U = padToLength("AAAAAAAARecord 1 updated", lrecl)

.getBytes(ZFile.DEFAULT_EBCDIC_CODE_PAGE);

nUpdated = zfile.update(rec_1U);

check("update len", lrecl == nUpdated);

// read back the record and verify its contents

check("Locate rec_1",

zfile.locate(rec_1, 0, keyLen, ZFile.LOCATE_KEY_EQ));

nRead = zfile.read(recBuf);

check("read len", lrecl == nRead);

check("rec_1U contents", Arrays.equals(rec_1U, recBuf));

// point to the second record, using alternate form of locate()

byte[] keybuf = new byte[keyLen];

System.arraycopy(rec_2, 0, keybuf, 0, keyLen);

check("Locate rec_2",

zfile.locate(keybuf, ZFile.LOCATE_KEY_EQ));

// read back the record and verify its contents

nRead = zfile.read(recBuf);

check("read len", lrecl == nRead);

check("rec_2 contents", Arrays.equals(rec_2, recBuf));

// update the second record, using the alternate update() form

byte[] rec_2U = padToLength("BBBBBBBBRecord 2 updated", lrecl)

.getBytes(ZFile.DEFAULT_EBCDIC_CODE_PAGE);

nUpdated = zfile.update(rec_2U, 0, rec_2U.length);

check("update len", lrecl == nUpdated);

// read back the record and verify its contents

check("Locate rec_2",

zfile.locate(rec_2, 0, keyLen, ZFile.LOCATE_KEY_EQ));

nRead = zfile.read(recBuf);

check("read len", lrecl == nRead);

check("rec_2U contents", Arrays.equals(rec_2U, recBuf));

// delete all of the records

check("Locate rec_1",

zfile.locate(rec_1, 0, keyLen, ZFile.LOCATE_KEY_EQ));

nRead = zfile.read(recBuf); // have to read a rec b4 updating

zfile.delrec();

check("Locate rec_2",

zfile.locate(rec_2, 0, keyLen, ZFile.LOCATE_KEY_EQ));

nRead = zfile.read(recBuf);

zfile.delrec();

check("Locate rec_3",

zfile.locate(rec_3, 0, keyLen, ZFile.LOCATE_KEY_EQ));

nRead = zfile.read(recBuf);

zfile.delrec();

// verify that we get an exeception if we try to delete without

// reading one first

try {

zfile.delrec();

check("Expected exception from delrec()", false);

} catch (ZFileException zfe ) {

System.out.println("Expected exception: " + zfe);

check("zfe.getErrno = " + zfe.getErrno(),

76 == zfe.getErrno());

}

// check that a record that was deleted cannot be found

check("Locate rec_2 after deleting",

! zfile.locate(rec_2, 0, keyLen, ZFile.LOCATE_KEY_EQ));

} finally {

zfile.close();

}

/**

* Pad a string with spaces to a specified length

static String padToLength(String s, int len) {

StringBuffer sb = new StringBuffer(len);

sb.append(s);

for (int i = s.length(); i < len; i++) sb.append(' ');

return sb.toString();

}

/**

* Check a condition and throw an Exception with message if not true

static void check(String msg, boolean value) {

if (!value) throw new RuntimeException(msg);

}

java-samples/ZFileKSDS.java at master · zsystems/java-samples · GitHub

Expand file tree

Breadcrumbs

ZFileKSDS.java

Latest commit

History

Breadcrumbs

ZFileKSDS.java

File metadata and controls