http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); HLz<C
} ha|2u(4
for(int i=0;i<nEndPos.length-1;i++) \mu';[gLd
{ vM5I2C3_>!
nEndPos = nStartPos[i+1]; @=w)a
} {(-923|,
nEndPos[nEndPos.length-1] = nFileLength; 0y<9JvN$9
} 9Oj b~
} Mz$qe
b/\O;o}]
Z(RsB_u5
//启动子线程 )x[=}0C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m`zd0IRTP
for(int i=0;i<nStartPos.length;i++) w7~]c,$y.
{ chD7^&5]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bny@AP(CY+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _Q^jk0K8ga
nStartPos,nEndPos,i); =aj|auu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &/uakkS
fileSplitterFetch.start(); U[;ECw@
} exSwx-zxI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TuCHD~rb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1c"s+k]9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o/ \o-kC}
nEndPos = " + nFileLength); 6flO;d/v
// fileSplitterFetch[nPos.length-1].start(); Us "G X_
Ap\]v2G
3@eI?(N
//等待子线程结束 Kg2@]J9m
//int count = 0; Vt zSM%=
//是否结束while循环 xF) .S@
boolean breakWhile = false; *]q`:~u2
</<z7V,{
n@@tO#!\
while(!bStop) tZ=|1lM
{ /Tl ybSC1
write_nPos(); )N{PWSPs
Utility.sleep(500); ]igCV
breakWhile = true; Th,]nVsGs~
E.$//P n|1
eWYet2!Q
for(int i=0;i<nStartPos.length;i++) `mAYK)N
{ ]lJ#|zd8o
if(!fileSplitterFetch.bDownOver) >oy%qLHe~t
{ Jp)PKS ![
breakWhile = false; Gg6cjc=dC
break; \K9Y@jnr
} coaJDg+
} '%Oo1:wJ
if(breakWhile) $?: -A
break; b,HXD~=
&C,]c#-+
3S^Qo9S
//count++; YA8/TFu<_
//if(count>4) mNe908Yw
// siteStop(); m|cRj{xZF
} 3s:)CXO
<C"}OW8
Obc,
System.err.println("文件下载结束！"); N]c:8dOj
} /%?bO-
catch(Exception e){e.printStackTrace ();} >)+U^V
} uTbMp~cYB
*qMjoP,
~U?vB((j!
//获得文件长度 &n6 |L8
public long getFileSize() u_WW uo
{ NFIFCy!
int nFileLength = -1; }?{. 'Hv0
try{ T^xp2cZ
URL url = new URL(siteInfoBean.getSSiteURL()); d9D*w/clMi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #2.C$
httpConnection.setRequestProperty("User-Agent","NetFox"); 5hCfi
^kB9 I8u
0Z%<H\Z
int responseCode=httpConnection.getResponseCode(); P#A|Pn<p
if(responseCode>=400) 8r\xQr'8h
{ Q"xDRQA
processErrorCode(responseCode); jTQN(a9Y
return -2; //-2 represent access is error Pt;\]?LVrD
} ~ C_2D?
Q%GLT,f1.
^eYJ7&t
String sHeader; f'Xz4;
1^;&?E
8{Svax(
for(int i=1;;i++) I#p-P)Q%S
{ v#sx9$K T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^T@-yys
//Utility.log(in.readLine()); .fW`/BXE
sHeader=httpConnection.getHeaderFieldKey(i); V|0UwS\n
if(sHeader!=null) VKrKA71Z~
{ Z3T26Uk
if(sHeader.equals("Content-Length")) / dn]`Ge)
{ R91u6r#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3^&pb
break; t;ga>^NA"
} RzSN,bLR
} p7O4CP>9[
else U`'w{~"D%
break; :(x 90;DW
} !C0= h
} b}q,cm
catch(IOException e){e.printStackTrace ();} WUi7~Ei}
catch(Exception e){e.printStackTrace ();} %}&9[#
L'h'm{i
xhMdn3~U
Utility.log(nFileLength); 2I39fZa
Y!s/uvRI
V'?nS&,i
return nFileLength; WqU$cQD"
} 5O%}.}n
*m]%eU(
|b7>kM}"
//保存下载信息（文件指针位置） {k~$\J?.
private void write_nPos() ae1fCw3k
{ ]R]X#jm
try{ 9p$q@Bc
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8@Km@o]?
output.writeInt(nStartPos.length); J5rR?[i{
for(int i=0;i<nStartPos.length;i++) )'<zC
{ bm7$DKp#
// output.writeLong(nPos); r*3XM{bZ/@
output.writeLong(fileSplitterFetch.nStartPos); QnOa?0HL/
output.writeLong(fileSplitterFetch.nEndPos); p|bpE F=U
} ~E`A,
output.close(); IweQB}d
} uTJ?@^nq
catch(IOException e){e.printStackTrace ();} Cw^)}23R
catch(Exception e){e.printStackTrace ();} EGMcU|yL
} wy&*6>.
T@HozZ
#QDV_ziE5
//读取保存的下载信息（文件指针位置） Pr/&p0@aV
private void read_nPos() CC87<>V
{ nocH~bAf2
try{ 1Q;`<=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )DLK<10
int nCount = input.readInt(); 3i$AR
nStartPos = new long[nCount]; rC*nZ*
nEndPos = new long[nCount]; |$0/:*
for(int i=0;i<nStartPos.length;i++) SI(8.$1
{ |m EJJg`"7
nStartPos = input.readLong(); %yrP: fg/
nEndPos = input.readLong(); g%[Ruugu
} IH0^*f
input.close(); nMbV{h ,
} #5I "M WA
catch(IOException e){e.printStackTrace ();} r#~6FpFVK^
catch(Exception e){e.printStackTrace ();} `4p9K
} vA{[F7
u1kbWbHu(
[E/3&3
private void processErrorCode(int nErrorCode) Mo<p+*8u:
{ ffhD+-gTU
System.err.println("Error Code : " + nErrorCode); nz&JG~Qfm
} Yr,1##u
^~I
5astv:p,P
//停止文件下载 |3cR'|<Ual
public void siteStop() )T+htD)
{ J\0YL\jw1K
bStop = true; y@z#Jw<
for(int i=0;i<nStartPos.length;i++) ^b.J z}
fileSplitterFetch.splitterStop(); y|mR'{$I
gy[uqm_ T
\ a<Ye T
} 1wM p3
} s`2o\]
//负责部分文件的抓取 87/{\h
**FileSplitterFetch.java ZqGq%8\.s
*/ D.GSl
package NetFox; u!S{[7 FY
A|+{x4s`
Aws TDM
import java.io.*; _[7uLWyC9
import java.net.*; Q&LkST-i
EkBM>*W
mnia>; 0H
public class FileSplitterFetch extends Thread { J{ Vl2P?@
#75;%a8
Mf63 59
String sURL; //File URL tpctz~ .
long nStartPos; //File Snippet Start Position *dl@)~i
long nEndPos; //File Snippet End Position ,O+7nByi[V
int nThreadID; //Thread's ID 1$W!<:uh
boolean bDownOver = false; //Downing is over ~}116K
boolean bStop = false; //Stop identical M/qiA.C@W
FileAccessI fileAccessI = null; //File Access interface *$1)&2i
5%$#3LT|
3WYW])
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m}E$6E^~O
{ koU.`l.
this.sURL = sURL; '$VR_N\
this.nStartPos = nStart; hg~fFj3ST
this.nEndPos = nEnd; ]=3O,\
nThreadID = id; J@fE")
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V_QVLW
} k|D!0^HE[
.,,73"
.wSAysiQ|P
public void run() F*=RP$sj
{ B+LNDnjO]
while(nStartPos < nEndPos && !bStop) 1d"P) 3dQ
{ Y4O L 82Y
'9gI=/29D
uwka 2aSS
try{ |<0@RCgM
URL url = new URL(sURL); KPhqD5, (
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *GhRU5
httpConnection.setRequestProperty("User-Agent","NetFox"); on\\;V_/Q
String sProperty = "bytes="+nStartPos+"-"; >R<fm
httpConnection.setRequestProperty("RANGE",sProperty); _<7FR:oBZ
Utility.log(sProperty); #u$z-M !
`vSsgG
K/-D 5U
InputStream input = httpConnection.getInputStream(); [1U_c*;i
//logResponseHead(httpConnection); DvCt^O*
a6d KQ3D
I'C,'
byte[] b = new byte[1024]; lUEyo.xVt
int nRead; 7w*&Yg]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :S12=sFl$
{ ?+\,a+46P_
nStartPos += fileAccessI.write(b,0,nRead); \YS?}! 0
//if(nThreadID == 1) nz\fN?q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <GN?J.B
} De_</1Au!2
8rYK~Sz
%-Z~f~<?
Utility.log("Thread " + nThreadID + " is over!"); w$4Lu"N:
bDownOver = true; ULjzhy+(8
//nPos = fileAccessI.write (b,0,nRead); !Xi>{nV
} d#Ajb
catch(Exception e){e.printStackTrace ();} Kc0OLcu^d
} vp@+wh]#
} =*Xf(mhc
MjTKM;
Hi9z<l=$
//打印回应的头信息 h'p0V@!N
public void logResponseHead(HttpURLConnection con) ;>9pJ72r
{ rE:>G]j6
for(int i=1;;i++) ~~,<+X:
{ : 4WbDeR
String header=con.getHeaderFieldKey(i); Uj)]nJX
if(header!=null) iurB8~Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }i:'f2/
Utility.log(header+" : "+con.getHeaderField(header)); VHCzlg
else h6i{5\7.
break; Gu).*cU
} rR~X>+K
} H)Ge#=;ckQ
P;&p[[7
F.D1;,x
public void splitterStop() ud D[hPJd
{ H@' @xHv
bStop = true; ;[ueNP%*y|
} I/jr`3Mj
XD}_9p
Yur)_m
} @/L. BfTz
{2^@jD
+hgCk87%#
/* VYo;[ue([
**FileAccess.java dy?|Q33Y"
*//文件访问(定位，写) XH$|DeAFM
package NetFox; q&T'x> /
import java.io.*; f*}E\,V"&
CJ
/ASI0h
public class FileAccessI implements Serializable{ Tpx,41(k
98'XSL|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #/<Y!qV&
RandomAccessFile oSavedFile; 4 GW[GT
long nPos; g}QTZT8
I>Fh*2
a&Du5(r;!
public FileAccessI() throws IOException XF$]KAL0
{ z %E!tB2o
this("",0); C&N4<2b
} s,H(m8#>
C)p<M H<
%5?-g[
public FileAccessI(String sName,long nPos) throws IOException &W// Ox )f
{ 4^_Au^8R(
oSavedFile = new RandomAccessFile(sName,"rw"); 9?chCO(@
this.nPos = nPos; .MARF
oSavedFile.seek(nPos); _4B iF?1
} ^)^|;C\`
W r7e_
_kX/LR"L+
public synchronized int write(byte[] b,int nStart,int nLen) 5XO'OSdYq
{ eAKQR
int n = -1; !&p:=}s
try{ U] -@yx
oSavedFile.write(b,nStart,nLen); f?zK"
n = nLen; W;]UP$5l
} ./y[<e
catch(IOException e) ]V^.!=gh$
{ 6v O)s!b
e.printStackTrace (); 6-14Htsk6
} Ds,"E#?
h=r< B\Pa
P3ev4DL
return n; wf<`J/7u
} Tc5OI'-V
>@"3Q`
IYg3ve`x
} BBE1}V!u
^^3va)1{!
ZfCr"aL
/* gdFoTcHgO|
**SiteInfoBean.java NG!cEo:2aa
*/ 3nC#$L-
package NetFox; #r^@*<{^
Yk@s"qm3
::Q);
public class SiteInfoBean { G|oB'~{&
&\lS
-L3 |9k
private String sSiteURL; //Site's URL pXj/6+^
private String sFilePath; //Saved File's Path Q*&aC|b&
private String sFileName; //Saved File's Name ^'53]b:
private int nSplitter; //Count of Splited Downloading File SOQ-D4q
vp75u93
2n;;Tso"
public SiteInfoBean() \{=`F`oB=
{//nSplitter的缺省值为5 m<,G:?RM
//default value of nSplitter is 5 3et2\wOX1x
this("","","",5); V&j.>Y
} C\^<v&
A.C278^O8
\R>5F\ 0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DEp%\sj?
{ lJ]\
sSiteURL= sURL; 4OZ5hH h
sFilePath = sPath; IL2Gsj)M
sFileName = sName; O-!fOdX8_k
this.nSplitter = nSpiltter; 2|H91Y2
9eN2)a/
VO;UV$$
} |]!Ky[P
Pzm!`F^r}
BOiz ~h6
public String getSSiteURL() s!;VUr\
{ wH_n$w
return sSiteURL; iraRB~
} -=t3O#
1QF*e'
.m]=JC5'
public void setSSiteURL(String value) m`\i+
{ PVS<QN%
sSiteURL = value; )4L%zl7
} V3A>Ag+^~
*v nxP9<
Rp`_Grcd
public String getSFilePath() +`s&i%{1>
{ h6T/0YhWLP
return sFilePath; ['OCw {<
} 1S[5#ewB;j
Ux)p%-
q4.dLU,1
public void setSFilePath(String value) 'f?&EsIV?
{ eFj6p<
sFilePath = value; _z(5e
} ?y*+^E0
6`4W,
Y zBA{FE
public String getSFileName() /@:up+$
{ nc\C4g
return sFileName; ? __aVQ7
} d7_g u
0n<(*bfW
w^dueP7J
public void setSFileName(String value) $uFh$f
{ Q{l*62Bx
sFileName = value; v<7Gln
} Ub'%pU
^`jZKh8)h
;&W;
public int getNSplitter() lR@i`)'?U
{ $nfBvf
return nSplitter; ^L8Wn6s'
} <h@z=ijN
l\=-+'Y
NHFEr
public void setNSplitter(int nCount) Bd[L6J)
{ a:-)+sgHw
nSplitter = nCount; aZawBU.:
} yA?ENAM
} NO+ 55n
{n'qKurxY
n(Q\',C
/* sR>`QIi(a
**Utility.java m,@1LwBH
*/ F[7Kw"~J
package NetFox; ( *9Ip
M)`HK .
}l}yn@hYC
public class Utility { W) 33;E/}
0tW<LR-}E
?}=-eJ(7e
public Utility() dDqr B-G
{ *1Ut}
CCW%G,$U9
)@<HCRQ'q
} pyg!rf-
YH'$_,8peM
//线程睡眠 0HHui7Yy>
public static void sleep(int nSecond) uOG-IHuF
{ P>{US1t
try{ 42V,PH6o
Thread.sleep(nSecond); X/E7o92\
} `sk!C7%
catch(Exception e) 3qAwBVWa
{ {*?sVAvj
e.printStackTrace (); y^mWG1"O
} V\@jC\-5Vt
} N;Z`%&
*?^Z)C>
//日志 Sg.+`xww3
public static void log(String sMsg) e$Xq
{ C5PmLiOHY>
System.err.println(sMsg); 4-7kS85
} |RR%bQ^{
1jH7<%y
6WE&((r^
public static void log(int sMsg) ^s^JzFw
{ 2gd<8a''
System.err.println(sMsg); 861i3OXVE>
} ;m@1Ec@*p
} Qy=HrL]x
kgbobolA
Y{k>*: Ax_
/* HYjMNj0
**TestMethod.java s;fVnaqG:
*/ eeW' [
package NetFox; LbJtpwz>z
)\T@W
$^W-Wmsz
public class TestMethod { F . K2
5l41Q
On{~St'V
public TestMethod() gohAp
{ ///xx/weblogic60b2_win.exe ]ZzoJ7lr
try{ $?FS00p*|X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AVXX\n\_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `y\*m]:
SiteFileFetch fileFetch = new SiteFileFetch(bean); ds*m6#1b
fileFetch.start(); O^.%C`*
} a'@-"qk
catch(Exception e){e.printStackTrace ();} $uEJn&n7}
Xw7{R
'oz hz2s
} ^ckj3Y#;
Yv)Bj
)t|^Nuj8
public static void main(String[] args) iD>G!\&
{ T)WZ_bR
new TestMethod(); Y]C;T
} hc-lzYS
} XzlKP;r0
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