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)); N|$5/bV
} 9 R
for(int i=0;i<nEndPos.length-1;i++) EP(Eq
{ CdNih8uG
nEndPos = nStartPos[i+1]; Pr2;Kp
} I5Q~T5Ar
nEndPos[nEndPos.length-1] = nFileLength; 5v+L';wx[T
} 1xIFvXru
} <uC<GDO
E$R_rX4x
pkW5D
//启动子线程 VW~Xbyf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VRB~7\A5<)
for(int i=0;i<nStartPos.length;i++) {Y^c*Iqn
{ ozuIwzi7N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fQ1 0O(`g,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), j<@fT ewZ
nStartPos,nEndPos,i); W.p66IQwL&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T1bFxim#b
fileSplitterFetch.start(); pW7kj&a_.
} );!dg\U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `^zQ$au'u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FTbtAlqh<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }|,EU!nDi
nEndPos = " + nFileLength); rXuAixu!t
// fileSplitterFetch[nPos.length-1].start(); {<r`5
UC(9Dz
*.xZfi_|
//等待子线程结束 ij!*CTG
//int count = 0; 7G2vYKC'
//是否结束while循环 IX?@~'
boolean breakWhile = false; egbb1+tY
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"!^c
while(!bStop) 'cYQ?;
{ C?S~L5a#oC
write_nPos(); u,\xok"
Utility.sleep(500); _Po#ZGm~
breakWhile = true; xp(mB7;:
HI z9s4Y_
ZRUh/<\[
for(int i=0;i<nStartPos.length;i++) [C2kK *JZ
{ I IYLA(
if(!fileSplitterFetch.bDownOver) AsD1-$
{ $=lJG(2%
breakWhile = false; UFos E|r:
break; +*<K"H|,
} @ E >eq.m
} 0T=jR{j!o
if(breakWhile) K/~Y!?:Jr
break; C_C$5[~-:
O4n8MM|`
]2P/G5C3tU
//count++; b~F!.^7Q
//if(count>4) 1BTgGF
// siteStop(); ~yd%~|
} W;91H'`?H
c_t7RWV}
Y5Ft96o))x
System.err.println("文件下载结束！"); 7f[8ED[4
} z(#=tC|
catch(Exception e){e.printStackTrace ();} aam1tm#Q
} JTjzT2`A.
8.PXTOhVL
ipfm'aQ
//获得文件长度 T4l-sJ'|
public long getFileSize() k-io$
{ $,g 3*A
int nFileLength = -1; n|J.)E.
try{ .\)--+(
URL url = new URL(siteInfoBean.getSSiteURL()); Dxz5NW4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gi;9 S
httpConnection.setRequestProperty("User-Agent","NetFox"); eK\|SQb
py}.00it
WT I'O
int responseCode=httpConnection.getResponseCode(); .HQVj'g
if(responseCode>=400) on6<l
{ .0?ss0~
processErrorCode(responseCode); xu`d`!Tx
return -2; //-2 represent access is error Vvxa.B
} 3LT+9ad2d
t CkoYrvT
anpJAB:1
String sHeader; _T_PX$B
)H.ubM1
[f/vLLK
for(int i=1;;i++) .QNjeMu.
{ 6vMDm0sv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z3Bo@`&?
//Utility.log(in.readLine()); S.qk%NTTD
sHeader=httpConnection.getHeaderFieldKey(i); t*eleNYeS~
if(sHeader!=null) U.d'a~pH
{ nl.~^CP
if(sHeader.equals("Content-Length")) S$Ns8=
{ =ZFcxGo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X+/{%P!w
break; 2Zv,K-G
} Mr#oT?
} nLzX Z6JlU
else V+P8P7y37B
break; /QV [N
} u Eu6f
} n$nne6|O
catch(IOException e){e.printStackTrace ();} cC7"J\+r*
catch(Exception e){e.printStackTrace ();} #rqyy0k0'h
"cIGNTLFA
mjWp8i
Utility.log(nFileLength); ^A:!ni@3
*2w_oKE'+5
eUzU]6h
return nFileLength; 2nG{>,#C:O
} 41P4?"O
1v>
WHZe)|n
//保存下载信息（文件指针位置） Y8x(#qp,
private void write_nPos() $71i+h]_
{ a*pXrp@
try{ -='8_B/75
output = new DataOutputStream(new FileOutputStream(tmpFile)); g}\U, (
output.writeInt(nStartPos.length); ?6_"nT*}
for(int i=0;i<nStartPos.length;i++) Ah(\%35&
{ /zChdjz
// output.writeLong(nPos); t;Fbt("]:
output.writeLong(fileSplitterFetch.nStartPos); COxZ Q
output.writeLong(fileSplitterFetch.nEndPos); N]3-L`t
} +!mNm?H[!
output.close(); 'vqj5YTj
} i{%z
catch(IOException e){e.printStackTrace ();} ?,A}E|jZ
catch(Exception e){e.printStackTrace ();} I{i:B
} D5o+0R
03i?"MvNo
6Cop#kW#
//读取保存的下载信息（文件指针位置） <k!mdj)
private void read_nPos() 8=ukS_?Vy
{ c,g]0S?gu
try{ ,3fuX~g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); UKt/0Ze
int nCount = input.readInt(); ?qq!%4mTB
nStartPos = new long[nCount]; gxBl1
nEndPos = new long[nCount]; [Gh%nsH
for(int i=0;i<nStartPos.length;i++) B^Rw?:hN
{ ="'rH.n #
nStartPos = input.readLong(); $9j>VGf=
nEndPos = input.readLong(); QZ:]8MHl]
} i'eYmm96Q
input.close(); . }-@;:yh
} ovo?lE-a0
catch(IOException e){e.printStackTrace ();} H4,.H,PZ
catch(Exception e){e.printStackTrace ();} m!FM+kge
} iXr`0V
IPr*pQ{;c
(;Dn%kK
private void processErrorCode(int nErrorCode) Z L6~Eut
{ 5JXzfc9rL
System.err.println("Error Code : " + nErrorCode); u"Hd55"&
} <:kTTye|
]$XBd{\D{
cNuuzA
//停止文件下载 '6dD^0dZ
public void siteStop() Jq$6$A,f
{ softfjl&l
bStop = true; '.}6]l
for(int i=0;i<nStartPos.length;i++) s)`1Rf
fileSplitterFetch.splitterStop(); g4.'T51
{Q#Fen ;y|
IlC:dA
} SSA%1l2!
} h0Sy']3m
//负责部分文件的抓取 ((hJmaq
**FileSplitterFetch.java .SRuyioF&
*/ Fw_bY/WN{
package NetFox; )ZQ9a4%
Aoy1<8WP%
.zSimEOF
import java.io.*; l1iF}>F2
import java.net.*; %BKR}
#h #mOJ5
#1,>Qnl
public class FileSplitterFetch extends Thread { dwf #~7h_
FS]+s>
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String sURL; //File URL hK9t}NE.O
long nStartPos; //File Snippet Start Position J?qcRg`1E
long nEndPos; //File Snippet End Position ?Uy*6YS
int nThreadID; //Thread's ID YWn6wzu%Vc
boolean bDownOver = false; //Downing is over /!&b'7y
boolean bStop = false; //Stop identical c?V*X-
FileAccessI fileAccessI = null; //File Access interface 5qeS|]^`
R;Gl{
`|ck5DZT5L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6S+K*/w
{ yEw"8u'
this.sURL = sURL; X'3`Q S:!
this.nStartPos = nStart; 4Q`=t&u
this.nEndPos = nEnd; V.P5v{
nThreadID = id; 4LB9w21
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P*"AtZuY]
} &d|VH y+
2A18hP`^
LK-K_!F
public void run() x":Bw;~
{ =J[[>H'<d
while(nStartPos < nEndPos && !bStop) Zc' >}X[G
{ O>"r. sR
u;'<- _
*nUpO]
try{ T$N08aju#
URL url = new URL(sURL); 3Av(|<cR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2*7s9g
httpConnection.setRequestProperty("User-Agent","NetFox"); T0]%(F/8
String sProperty = "bytes="+nStartPos+"-"; ;]#4p8lh+
httpConnection.setRequestProperty("RANGE",sProperty); r* /XB0
Utility.log(sProperty); }T1Xds8w)t
P20]>Hg
0F0(]7g^
InputStream input = httpConnection.getInputStream(); AN:RY/ %Wo
//logResponseHead(httpConnection); <DlanczziF
]rX?n
}9+1<mT9a/
byte[] b = new byte[1024]; 'i h
int nRead; 3{#pd6e5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g$^qQs)^N
{ WNlSve)]ie
nStartPos += fileAccessI.write(b,0,nRead); lh(+X-}D
//if(nThreadID == 1) v BeU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C$re$9U
} OSh mrz28
f29HQhXqS
@!O&b%8X%
Utility.log("Thread " + nThreadID + " is over!"); J ]l@ r
bDownOver = true; 51;%\@=
//nPos = fileAccessI.write (b,0,nRead); [k&s!Qp
} rEpKX
catch(Exception e){e.printStackTrace ();} vdFQf ^l
} V.a]IkK'K
} h C`p<jp/
B| 0s4E
j C1^>D
//打印回应的头信息 jv#" vQ9A]
public void logResponseHead(HttpURLConnection con) aXid;v,
{ &+w!'LSaD
for(int i=1;;i++) 1r:fxZO\Vd
{ 7J!d3j2TR
String header=con.getHeaderFieldKey(i); *,XJN_DKj
if(header!=null) =iN_Ug+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vJjj+:
Utility.log(header+" : "+con.getHeaderField(header)); qD>Y}Z!
else WZ V*J&
break; .=w`T #L
} Ckl]fy@D}
} JU2' ~chh
)yH#*~X_
<x;[ H%
public void splitterStop() 5J2p^$s
{ \iLd6Qo_aq
bStop = true; "YvBb:Z>
} GC#95
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AJ1$$c
} z'}t@R#H
:IKp7BS
89e.\EH
/* ;\&bvGj8V
**FileAccess.java l0bT_?LhK
*//文件访问(定位，写) 5xV/&N
package NetFox; ~~E=E;9
import java.io.*; 8; N}d)*O
owVUL~
c94PWPU
public class FileAccessI implements Serializable{ cFNtY~(b
3&d+U)E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 eOmxA<h
RandomAccessFile oSavedFile; T-cVM>u\D
long nPos; GKDG5u;
op{(mn
0QSi\: 1f
public FileAccessI() throws IOException {1&,6kJF&9
{ a}]@o"
this("",0); &aht K}u
} lukRFN>c"
G uI sM
/OtQk-E
public FileAccessI(String sName,long nPos) throws IOException iQR})=Q
{ jQlK-U=oi
oSavedFile = new RandomAccessFile(sName,"rw"); rG%_O$_dO
this.nPos = nPos; SmEd'YD!J
oSavedFile.seek(nPos); pq5H{
} wDTV /"Y
g wiC ,
2Yf;b9-k
public synchronized int write(byte[] b,int nStart,int nLen) IHMyP~{
{ 2x J5
int n = -1; >\Pj(,'
try{ ]6 7wk
oSavedFile.write(b,nStart,nLen); lMf5F8
n = nLen; , &f20o
} )8>f
catch(IOException e) O g~"+IGp
{ PvCE}bY{}
e.printStackTrace (); v2z/|sG
} )bg,rESM
Jg6[/7*m
oRF"[G8BV
return n; iiFKt(
} AiI# "
~Q\ZDMTK
+~AI(h
} 'bO? =+c
8LKZ3Y|
lLf01sa4
/* ]/naH#8G
**SiteInfoBean.java J}u1\Id%
*/ \ku{-^7
package NetFox; AlhiF\+ C
ZDD|MH
5gEWLLDp
public class SiteInfoBean { 8jx1W9=`9[
^>28>!"1
hfc!M2/w
private String sSiteURL; //Site's URL @Ec9Do>
private String sFilePath; //Saved File's Path P &._-[
private String sFileName; //Saved File's Name wd0ACF
private int nSplitter; //Count of Splited Downloading File WSwmX3rn
Vjd =F.V+
m$: a|'mS
public SiteInfoBean() ~q>ilnL"h
{//nSplitter的缺省值为5 73`UTXvWU
//default value of nSplitter is 5 1mM52q.R4
this("","","",5); |B.d7@{mM
} q|2C>{8
,DZLEsFM
&Wk<F3qN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5X-(@GwN
{ VlNzm
sSiteURL= sURL; Sw)ftC~d
sFilePath = sPath; 03;(v%
sFileName = sName; FZ/&[;E!
this.nSplitter = nSpiltter; =w>QG{-N
#pFybk
\2b9A'd>
} Ut=y`]F
a{,t@G
GUXX|W[6
public String getSSiteURL() xFnMXht
{ F,:VL*.5kJ
return sSiteURL; sl 5wX
} !7DS
nQ6'yd"
}@4*0_g"Aw
public void setSSiteURL(String value) ?[">%^
{ 5gEK$7Vp
sSiteURL = value; vX%gcs/@
} ZQ/5]]}3y
$!@f{9+
7 #N @B
public String getSFilePath() c6|&?}F
{ O}V2>W$
return sFilePath; \O~P !`
} B~rK3BS
J-c7ZcTt
2S/7f:
public void setSFilePath(String value) ZC-N4ESr
{ zYsGI<4
sFilePath = value; q[ZYlF,Ho
} }J`Gm
V5MbWXgR
Hua8/:![+
public String getSFileName() h,g~J-x`|
{ g!uhy}
return sFileName; ER+[gT1CQ
} -9EbU7>!
F\;1:y~1
tWuQKN`_
public void setSFileName(String value) qE[}Cf]X
{ jF8ld5|_|
sFileName = value; @P?*<b{
} ^D)C|T
%94"e7Hy
#oI`j q
public int getNSplitter() I%Z&i-33y
{ C&gJP7UF
return nSplitter; W0k_"uI
} 2~ a4ib
ly2R8$Y`y`
,D1QJPM
public void setNSplitter(int nCount) |HLh?AcX
{ C{-pVuhK+
nSplitter = nCount; 3@PVUJ0B|
} Kt(p|
} z,WrLZC
paY%pU
@z.!Dby
/* t{9Ph]e
**Utility.java |Z;Av%%
*/ dhbJ1/z^
package NetFox; ux=@"!PJ
S{ !hpq~o
(TPD!=
public class Utility { Bb)J8,LQ
n)yqb
Uka4iya
public Utility() Qi M>59[
{ 81&!!qhfS
i2DR}%U
)? xg=o/?
} I g`#U~
-zt\weqA
//线程睡眠 |d$aISO`
public static void sleep(int nSecond) #,sJd^uI
{ :L,]<n
try{ We|*s2!
Thread.sleep(nSecond); ^H'#*b0u
} K^+B"
catch(Exception e) Q5ux**(Wr
{ (@ Bw@9
e.printStackTrace (); 9Bn dbSi
} %zGPF
} Rp#SqRy`
=g ]C9'I3
//日志 QnqX/vnR
public static void log(String sMsg) ,=FYf|Z
{ %2.T1X%!
System.err.println(sMsg); ^VQiq7 xm
} *T3"U|0_y
n(L {2r
;8!D8o(+
public static void log(int sMsg) +=O:z *O
{ ;iEqa"gO
System.err.println(sMsg); E_? M&
} <]<50
} _+U`afV
Pdv&X*KA
&8N\ 6K=
/* U!h!z`RU54
**TestMethod.java 5g=" #
*/ ],LOkAX
package NetFox; >v(Xc/oI
0o#lB^e;l
m$kmoY/
public class TestMethod { 6-oQs?
` H"5nQRV
NQb?&.C
public TestMethod() 8/=2N
{ ///xx/weblogic60b2_win.exe L.5GX 29
try{ c;WS !.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w v1R ]3}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Sdn] f4
SiteFileFetch fileFetch = new SiteFileFetch(bean); ."2V:;;
fileFetch.start(); .]" o-(gB
} )}EwEM
catch(Exception e){e.printStackTrace ();} 87-oR}/r
Y=5hm
rkD(KG9E
} ka(xU#;
3cnsJV]
Y{jhT^tKK
public static void main(String[] args) N.fIg
{ uaS?y1:c
new TestMethod(); V{8mx70
} V/03m3!q
} >uVG]
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