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)); |A+,M"F?
} J-5kvQi8
for(int i=0;i<nEndPos.length-1;i++) e-VGJxR
{ 7=&+0@R#/d
nEndPos = nStartPos[i+1]; ;*=7>"o'`
} %CUwD
nEndPos[nEndPos.length-1] = nFileLength; =T)y(] ;M$
} @![1W@J
} DUg[L
w>'3}o(nY
`91Z]zGpU
//启动子线程 hb9HVj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0vMKyT3 c
for(int i=0;i<nStartPos.length;i++) vTL/% SJ8
{ `_BmVms
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BbPRPkV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [e{D
nStartPos,nEndPos,i); JEP9!y9y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RPjw12Ly
fileSplitterFetch.start(); EZT 8^m
} Q9;VSF)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *Y!RU{w+Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); b~<:k\EE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f>&*%[fw
nEndPos = " + nFileLength); *<}R=X.
// fileSplitterFetch[nPos.length-1].start(); 46B'Ec
Q:'r p
BH}M]<5
//等待子线程结束 tGSXTF}G
//int count = 0; *_H]?&
//是否结束while循环 ][XCpJ)8
boolean breakWhile = false; 5@pLGMHT
(CAkzgTfc
&[N_{O|
while(!bStop) ,kl``w|1M
{ >\3N#S"PF
write_nPos(); j9-.bGtm?.
Utility.sleep(500); ;hh.w??
breakWhile = true; AOz~@i^
+4Q1s?`
7;Vmbt9
for(int i=0;i<nStartPos.length;i++) '?LqVzZI
{ -<e_^
if(!fileSplitterFetch.bDownOver) /"^XrVi-
{ +k0UVZZX?
breakWhile = false; ?30pNF|
break; h${=gSJc
} _SH~.Mt_!
} 7h>,
if(breakWhile) Zlygx
break; R0G!5>1i
>X5RRSo
Kk|)N3AV:
//count++; ;*d?Qe:
//if(count>4) sLSH`Xy?5
// siteStop(); d ]#`?}
} :b!&Xw$
9%m^^OOf
:'[ha$
System.err.println("文件下载结束！"); gJg+ ]-h/
} M'T[L%AP
catch(Exception e){e.printStackTrace ();} 5v sn'=yN
} 'aS: Azb
V >~\~H2Y
Zv9%}%7p
//获得文件长度 7ZUS
public long getFileSize() ~NO7@muw
{ 1O1MB&5%
int nFileLength = -1; -$,'|\Y
try{ Owv}lJ
URL url = new URL(siteInfoBean.getSSiteURL()); WHu[A/##']
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JIf.d($ ~:
httpConnection.setRequestProperty("User-Agent","NetFox"); 8x8nQ*_
S%wdXe
j%':M
int responseCode=httpConnection.getResponseCode(); x1"8K
if(responseCode>=400) N(O*"1b
{ NFf`V
processErrorCode(responseCode); tg9{(_t/W
return -2; //-2 represent access is error zQ(`pld
} !wZIXpeL
Pjq()\/[Z
UMHFq-
String sHeader; b=SCyGxlZ5
IBW-[lr7
`trcYmR=k
for(int i=1;;i++) 6LqF*$+$`
{ Hr \vu`p$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :!FGvR6
//Utility.log(in.readLine()); @ *5+ZAF
sHeader=httpConnection.getHeaderFieldKey(i); v"<M ~9T)
if(sHeader!=null) H8m[:K]_H
{ R{6M(!x
if(sHeader.equals("Content-Length")) } V"A;5j`
{ WE+Szg(4x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /4upw`35]
break; c@KNyBy2
} >GmO8dK
} &4*f28 s
else <y#@v G
break; N37CAbw0
} J6@RIia
} rmdg~
catch(IOException e){e.printStackTrace ();} fVi[mH0=+
catch(Exception e){e.printStackTrace ();} MOm+t]vq1
z9v70 q
vOl3utu7
Utility.log(nFileLength); +=*ND<$n/E
//bQD>NBO
Fw^^sB
return nFileLength; b27t-p8
} Rhw+~gd*F
s~c cx"HH
KbH|'/w
//保存下载信息（文件指针位置） 6B}V{2
private void write_nPos() G}aM~,v
{ X<f4X"y
try{ Ty*+?#`
output = new DataOutputStream(new FileOutputStream(tmpFile)); n} ]gAX
output.writeInt(nStartPos.length); hb>uHUb&
for(int i=0;i<nStartPos.length;i++) m]}EVa_I`/
{ pezfB{x?
// output.writeLong(nPos); {J/+KK
output.writeLong(fileSplitterFetch.nStartPos); 7'ws: #pC
output.writeLong(fileSplitterFetch.nEndPos); }}Gkipp
} Vygh|UEo
output.close(); Gc;-zq
} /sqfw,h@
catch(IOException e){e.printStackTrace ();} f*^bV_
catch(Exception e){e.printStackTrace ();} SjcX|=S
} Ix0#eoj
h|<;:o?yh
`6PBV+]Vm3
//读取保存的下载信息（文件指针位置） 4I.)>+8V
private void read_nPos() \@zoM:[sN
{ \[/}Cy
try{ ^}<]sjmk
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C\0,D9
int nCount = input.readInt(); >}d6)s|
nStartPos = new long[nCount]; fr8';Jm
nEndPos = new long[nCount]; @[Wf!8_
for(int i=0;i<nStartPos.length;i++) cVSns\QO
{ GbvbGEG
nStartPos = input.readLong(); hK3Twzte
nEndPos = input.readLong(); 8L`wib2
} zv^+8h7k
input.close(); xJOp~fKG
} |{rhks~
catch(IOException e){e.printStackTrace ();} 6}*4co
catch(Exception e){e.printStackTrace ();} 4%6@MQ[
} 0;w84>M
^C}f|{J
\JP9lJ3<
private void processErrorCode(int nErrorCode) -tp3qi
{ T7(d
System.err.println("Error Code : " + nErrorCode); "i!W(}x+
} C\ 34R
'yh)6mid
+u lxCm_lV
//停止文件下载 %iZ~RTY6 !
public void siteStop() qr~zTBT] E
{ P75@Yu(
bStop = true; gmOP8.g
for(int i=0;i<nStartPos.length;i++) ~x J#NC+
fileSplitterFetch.splitterStop(); CU/Id`"tW
1`Uu;mz
A^4#6],%v
} s1X?]A
} ^xr &E
//负责部分文件的抓取 m,F4N$
**FileSplitterFetch.java "DRiJ.|APs
*/ B.);Ju
package NetFox; g$z6*bL
Ze?H
}xgs]\^,73
import java.io.*; dX-j3lM:#
import java.net.*; FQ/z,it_i
K'[kl'
)W1[{?
public class FileSplitterFetch extends Thread { vI(CX]o
q%XjJ -s:
@J6V,
String sURL; //File URL C *7x7|z
long nStartPos; //File Snippet Start Position 9q2x}
long nEndPos; //File Snippet End Position cxIAI=JK
int nThreadID; //Thread's ID z\K-KD{Ad
boolean bDownOver = false; //Downing is over K)eyFc
boolean bStop = false; //Stop identical .AF\[IQ
FileAccessI fileAccessI = null; //File Access interface k~JTQh*,w
( ;KTV*1
On,z#A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CH6;jo]
{ 04a@
this.sURL = sURL; 0Q]{r )
this.nStartPos = nStart; ,X\qlT5C
this.nEndPos = nEnd; T|5uywA|
nThreadID = id; .RbPO#(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O81'i2MJ9
} uzS;&-nA
_iu^VK,}
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public void run() C`8.8
{ k?_uv
while(nStartPos < nEndPos && !bStop) k:&B b"
{ ZtpbKy!\$B
"}0)~,{xB
!z5Ozm+}
try{ -R`nitf
URL url = new URL(sURL); Y{8}z ZD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JRDIGS_~
httpConnection.setRequestProperty("User-Agent","NetFox"); c7R6.T
String sProperty = "bytes="+nStartPos+"-"; /^`do3a}
httpConnection.setRequestProperty("RANGE",sProperty); LXRIo2ynuw
Utility.log(sProperty); o3le[6C/8=
DyRU$U
8(H!iKHe
InputStream input = httpConnection.getInputStream(); =bQ\BY#
//logResponseHead(httpConnection); Bey9P)_Of
:=K+~?
gbu)bqu2x
byte[] b = new byte[1024]; z/pxZB~"
int nRead; 0 R>!jw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jori,"s
{ +Ecn
nStartPos += fileAccessI.write(b,0,nRead); qh6Q#s>tH
//if(nThreadID == 1) O/oLQoH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 161IWos
} QL-E4]
[`1@`5SL-
^,Ft7JAn
Utility.log("Thread " + nThreadID + " is over!"); :7s2M
bDownOver = true; B06W(y,3Q>
//nPos = fileAccessI.write (b,0,nRead); cfHtUv
} VzWH9%w
catch(Exception e){e.printStackTrace ();} '.7ER
} 2UTmQOm
} -LlS9[r0
1gX$U00:
:79u2wSh
//打印回应的头信息 ]'0}fuV
public void logResponseHead(HttpURLConnection con) <Q_E3lQy/
{ 48.4GwL7
for(int i=1;;i++) 1CS\1[E
{ N \woFrG
String header=con.getHeaderFieldKey(i); I@(3~ Ab
if(header!=null) *~zB{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w`F'loUEt
Utility.log(header+" : "+con.getHeaderField(header)); OK \9`
else 0 .ck!"h}
break; SjvSnb_3
} dfXBgsc6i
} :\%ZTBLL
(b7',:_U7
i`!>zl+D
public void splitterStop() xQNGlVipZ@
{ p,3}A(>
bStop = true; VP1z"j:
} Dp?lgw
,S&p\(r.
bMqFrG
} +*wo iSD
[*r=u[67F
?',GRaD
/* !fJy7Y
**FileAccess.java , Q)
*//文件访问(定位，写) x}uDW
package NetFox; p uW
import java.io.*; e1ExB#
$NBQv6#:
JHJ]BMm
public class FileAccessI implements Serializable{ /lc4oXG8
<Kk?BRxi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @u:q#b
RandomAccessFile oSavedFile; 43*;"w=
long nPos; lr)9U7
|W5lhx0U
Tz7|OV_W$
public FileAccessI() throws IOException USKC,&6&}
{ O]t)`+%q
this("",0); N,&bBp
} S>d7q
)gk tI!
gj4ONmY
public FileAccessI(String sName,long nPos) throws IOException }synU]^7\
{ *56q4\1
oSavedFile = new RandomAccessFile(sName,"rw"); Sd\oL*lN
this.nPos = nPos; 5-:H
oSavedFile.seek(nPos); `~h8D9G
} ov1#BeQ
ob9=/ R?i
Xvxrz{
public synchronized int write(byte[] b,int nStart,int nLen) [=>[2Ty
{ r>t|.=!
int n = -1; ;33SUgX
try{ |A2o$H
oSavedFile.write(b,nStart,nLen); S~^]ib0
n = nLen; /&5:v%L
} N"zl7.E
catch(IOException e) sc z8`%
{ .G>~xm0
e.printStackTrace (); t6~~s iQI'
} ogoEtKi
J4?SC+\
xo{z4W
return n; +; =XiB5R
} /$j,p E=
z h%b<
%:7/ym[
} .~|[* q\
ONLhQJCb
>P-'C^:V=
/* )ZpMB
**SiteInfoBean.java uC2qP)m,^
*/ DN;$->>
package NetFox; 9+~1# |
=27ZY Z
PrF('PH7i
public class SiteInfoBean { x#t?`
;ih;8
~$YasFEz
private String sSiteURL; //Site's URL 9-y<= )
private String sFilePath; //Saved File's Path Xet} J@C
private String sFileName; //Saved File's Name T^Hq 5Oy
private int nSplitter; //Count of Splited Downloading File ?]>;Wr
Ee=!bv(%70
3Q_)Xs r`
public SiteInfoBean() P,k=u$
{//nSplitter的缺省值为5 )Zrn?KM
//default value of nSplitter is 5 1JZhcfG
this("","","",5); _SQ]\Z
} |C7=$DgwY
S0;s 7X#c
cK'}+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;>Z0e`=
{ vH6.;j'^
sSiteURL= sURL; TU9$5l/;g
sFilePath = sPath; N'?#g`*KW
sFileName = sName; +<WNAmh
this.nSplitter = nSpiltter; Z;6?,5OSc
`(~oZbErM
8>DX :`
} cq8JpSB(
kM3#[#6$!
Jv~^hN2
public String getSSiteURL() s_U--y.2r(
{ s2 $w>L
return sSiteURL; LKst QP!I
} mA5sK?W
!ZayN
8aW<lu
public void setSSiteURL(String value) >&Vz/0
{ Y7 e1%,$v
sSiteURL = value; _]us1
} (_fovV=
aQ0pYk~(
iL'j9_w,
public String getSFilePath() l^rQo_alk
{ D~ 7W
return sFilePath; FMC]KXSd
} {G{>Qa|
`dIwBfg_
@[]#[7
public void setSFilePath(String value) G1wJ]ar
{ 24 RD
sFilePath = value; "fu@2y4^
} *4c5b'u
=lx~tSiS
c4}|a1R\=
public String getSFileName() cPX^4d~9
{ mH )i
return sFileName; Lg|]|,%e
} SxL/]jWR7
/$|-!e<5b\
o>HGfr,N
public void setSFileName(String value) |q Pu*vR
{ 2 e&M/{
sFileName = value; lDZ~
} l_zTpyOZ
Cw~fP[5XMF
t_\&LMD
public int getNSplitter() H"wIa8A
{ Rp6q)
return nSplitter; =|H.r9-PK6
} }w{E<C(M
x}#N?d
5X:3'*
public void setNSplitter(int nCount) /b410NP5
{ DDZnNSo<JQ
nSplitter = nCount; l6.&<0pLT
} ?3<Y/Vg%c
} Ka$lNL3<j
s$ ?;C
[ZS.6{vr
/* x::d}PP7
**Utility.java ,?wxW
*/ $5>m\wrl
package NetFox; ~Jlq.S'
Nf}i/
}Zfi/^0U
public class Utility { L),bPfz
r"dR}S.Uf
*TPWLR ^
public Utility() dEam|
{ Q|G|5X
DkW^gt
9G4os!x)
} xp*d:
IaO*{1re
//线程睡眠 q&^H" fF
public static void sleep(int nSecond) 6Ia[`xuL
{ 3=%G{L16-
try{ '30JJ0
Thread.sleep(nSecond); dcfwUjp[
} w4l]rH
catch(Exception e) gwFW+*h
{ 6xu%M&ht
e.printStackTrace (); OXbC\^qo@
} *?+2%zP
} N:,V{Pw
im F,8'
//日志 6rlvSdB
public static void log(String sMsg) ..=lM:13|
{ -jVg{f!
System.err.println(sMsg); :N'
} M%s!qC+
ovaX_d)cU
zo@,>'m
public static void log(int sMsg) 97pnq1b
{ f4vdJ5pV
System.err.println(sMsg); \\35} 9
} CjJ n
} Sp]ov:]%f
*p|->p6,u
m<!CF3g
/* #hXuGBZEI
**TestMethod.java !04^E
*/ }&%&0$%
package NetFox; |*L/ m0'L
Zt 1nH
m;PTO$--
public class TestMethod { IG~Zxn1o
!. :b}t
v+CW([zAx#
public TestMethod() PmT<S,}L
{ ///xx/weblogic60b2_win.exe o%K1!'
try{ pE$*[IvQ'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6mjD@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `0-i>>
SiteFileFetch fileFetch = new SiteFileFetch(bean); jRxzZt4
fileFetch.start(); jJ?G7Q5l
} u3sr"w&
catch(Exception e){e.printStackTrace ();} |V^f}5gd
l>)+HoD
%m$t'?
} 2 S2;LB
OOYdrv,
Vc+~yh.)
public static void main(String[] args) ;}k_
{ T;i+az{N:V
new TestMethod(); ?XVox*6K&
} ~O 4@b/!4
} i(xL-&{
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