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)); BP`UB
} Q,>AT$|
for(int i=0;i<nEndPos.length-1;i++) m#uutomi0
{ akR*|iK#b
nEndPos = nStartPos[i+1]; nv|&|6?`oK
} cB|](gWS~
nEndPos[nEndPos.length-1] = nFileLength; '{),gV.
} )pg?ZM9
} EM"YjC)F
U@H SU%H
h>4\I;Ij
//启动子线程 ]1X];x&e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yt&^i(
for(int i=0;i<nStartPos.length;i++) zzM 'uo
{ 6b@:La
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y8\44WKW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -q[?,h
nStartPos,nEndPos,i); lE4.O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^;L;/I[-
fileSplitterFetch.start(); gP`8hNwR
} }z}oVc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (%tKGeb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zI&oZH^vn
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E;k'bz
nEndPos = " + nFileLength); lV3\5AEW
// fileSplitterFetch[nPos.length-1].start(); J@52<.>6
g^=p)h3
SwLul4V
//等待子线程结束 TeQpmhN
//int count = 0; k<m{Wp;-
//是否结束while循环 ^[2A< g
boolean breakWhile = false; "Q^Ck7
8@Pv nOL
Or0=:?4`
while(!bStop) U5odSR$
{ 7&E3d P
write_nPos(); g$~ktr+%
Utility.sleep(500); 0X.pI1jCO
breakWhile = true; !M6*A1g5
L'.7V ~b{
aH*)W'N?
for(int i=0;i<nStartPos.length;i++) K%O%#Kk
{ BZe x
if(!fileSplitterFetch.bDownOver) kU0e;r1N
{ >k5nU^|B1
breakWhile = false; YRqIC -_
break; ]:d`=V\&N
} DR;rK[f
} h#a,<B|
if(breakWhile) s7[du_)
break; 8A#qbBD
>:WnCkbp
8i;EpAwB
//count++; {%*,KB>b
//if(count>4) 1TJ2HO=Y
// siteStop(); :2vk vLM
} B|zJrz0q3
_SY4Qs`d
-A^18r
System.err.println("文件下载结束！"); =Q>'?w>
} INZsDM 9
catch(Exception e){e.printStackTrace ();} LB1LQ0M
} D6fry\
Bvb.N$G
J'jwRn
//获得文件长度 B&3oo
public long getFileSize() @z[,w`
{ MOi.bHCQJP
int nFileLength = -1; fMgB!y"Em
try{ -PPH]?],
URL url = new URL(siteInfoBean.getSSiteURL()); *mwHuGbZed
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %5Q5xw]w3
httpConnection.setRequestProperty("User-Agent","NetFox"); 4>x]v!d
r)E9]"TAB
:sDE'o
int responseCode=httpConnection.getResponseCode(); ^E{M[;sF3y
if(responseCode>=400) >>22:JI`
{ M$iDaEu-
processErrorCode(responseCode); Y>W$n9d&G2
return -2; //-2 represent access is error :Yeo*v9
} ?tx%KU\3
B8_)I.
rKxIOJ,T
String sHeader; 6:_@;/03%
"x~VXU%xU
])Rs.Y{Q5
for(int i=1;;i++) =Y!x
{ YD>5zV%!D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RI.6.f1dy
//Utility.log(in.readLine()); f"i(+:la
sHeader=httpConnection.getHeaderFieldKey(i); <j\osw1R
if(sHeader!=null) i;Y3pF0%P
{ CWKN0HB
if(sHeader.equals("Content-Length")) /,Unp1D
{ v_=xN^R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !'m MGxkEb
break; FVY$A=G
} N!me:|Dn
} -QPM$
else xwvg@
break; d6RO2^
} ct o+W}k
} j`H5S
catch(IOException e){e.printStackTrace ();} itotn!Wb`
catch(Exception e){e.printStackTrace ();} {9mXJu$cc
dOG]Yjc
''.P=
Utility.log(nFileLength); b{+7sl
0 $Ygt0d
*aem5E`c
return nFileLength; t?&@bs5~g
} [v0[,K
7tZvz `\
SK][UxoHm
//保存下载信息（文件指针位置） b\ P6,s'(
private void write_nPos() dio<?6ZD9P
{ Nj5V" c
try{ {:@MBA34
output = new DataOutputStream(new FileOutputStream(tmpFile)); UYw_k\
output.writeInt(nStartPos.length); ` @PHV
for(int i=0;i<nStartPos.length;i++) k 'CM^,F&
{ PJ$C$G
// output.writeLong(nPos); .@5RoD[o
output.writeLong(fileSplitterFetch.nStartPos); LA +BH_t&
output.writeLong(fileSplitterFetch.nEndPos); >0XB7sC
} h=a-~= 8
output.close(); !<EQVqj6
} "J.7@\^ h/
catch(IOException e){e.printStackTrace ();} QXaE2}}P
catch(Exception e){e.printStackTrace ();} 5u:{lcC.X
} 'nx";[6(
'gD,HX
.,vF%pQ
//读取保存的下载信息（文件指针位置） ^i;y2c
private void read_nPos() O>vbAIu
{ .sqX>sU/]
try{ tJ qd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9y$"[d27;+
int nCount = input.readInt(); BH;7CK=7R
nStartPos = new long[nCount]; i!nPiac
nEndPos = new long[nCount]; Sd9%tO9mf
for(int i=0;i<nStartPos.length;i++) {J[5 {]Je[
{ QIb4ghm,
nStartPos = input.readLong(); NA/hs/ '
nEndPos = input.readLong(); ,ve$bSp
} N!=$6`d
input.close(); E0lro+'lS
} g~/@`Z2Y
catch(IOException e){e.printStackTrace ();} IncHY?ud<
catch(Exception e){e.printStackTrace ();} #P,C9OQD
} Q>QES-.l
_v\L'`bif
Shag4-*@hi
private void processErrorCode(int nErrorCode) vR*TW
{ %~{G*%:
System.err.println("Error Code : " + nErrorCode); =Z~nzyaN
} uG:xd0X+W
lYq/ n&@_1
QRw/d}8l
//停止文件下载 J;R1OJs S
public void siteStop() ]A.tauSW
{ :}n\ r/i
bStop = true; 9{(A-
for(int i=0;i<nStartPos.length;i++) ]ysEj3
fileSplitterFetch.splitterStop(); Wf>P[6
>P_/a,O8
2<X.kM?N{B
} s.{nxk.
} ?E2$
//负责部分文件的抓取 <<iwJ U%:
**FileSplitterFetch.java @TqqF:c7
*/ E4;@P']`
package NetFox; pf%B
5;4bZ3e,0
JsY|Fv
import java.io.*; 4],*y`& g
import java.net.*; g/_j"Nn
->q^$#e
mAZfo53
public class FileSplitterFetch extends Thread { dPx{9Y<FzU
V W2+ Bs}
na)-'
String sURL; //File URL a%igc^GS2
long nStartPos; //File Snippet Start Position []#>r k~
long nEndPos; //File Snippet End Position W_\~CntyZ
int nThreadID; //Thread's ID #J_+ SL[
boolean bDownOver = false; //Downing is over \])-Bp,
boolean bStop = false; //Stop identical or)v:4PXW
FileAccessI fileAccessI = null; //File Access interface \YN(rD-
BJ,D1E
s ~Xa=_+D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k&dLg5O
{ ;+6TZqklQ
this.sURL = sURL; ROWrkJI>i
this.nStartPos = nStart; ,fR/C
this.nEndPos = nEnd; a|u&N:v7B
nThreadID = id; *F)+- BB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WNo",Vc
} Kx<T;iJ}
kE`V@F
iFBH;O_~
public void run() 6U!zc]>
{ :3h'Hr
while(nStartPos < nEndPos && !bStop) I4RUXi 5
{ 3Y6W)$Q
Ao}J
M"l<::z
try{ 1:Dm,d;
URL url = new URL(sURL); Q(0eq_X|6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |(Q !$
httpConnection.setRequestProperty("User-Agent","NetFox"); rfwX:R6,g
String sProperty = "bytes="+nStartPos+"-"; J\fu6Ti
httpConnection.setRequestProperty("RANGE",sProperty); z!> H^v
Utility.log(sProperty); ;:l>Kac
_ giZ'&l!
Rk(2|I
InputStream input = httpConnection.getInputStream(); y%NZ(Y,v
//logResponseHead(httpConnection); bxFDB^
KvtX>3#qM
n `Ry!
byte[] b = new byte[1024]; lAZn0EU
int nRead; KsR^:_e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B(/)mB
{ s;NPY
nStartPos += fileAccessI.write(b,0,nRead); Bq 9Eu1
//if(nThreadID == 1) *B ]5K{N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !^m,v19Ds<
} =xX)2h
~P5;k_&
Uc>$w?oA
Utility.log("Thread " + nThreadID + " is over!"); 25m6/Y
bDownOver = true; 3<vw#]yL
//nPos = fileAccessI.write (b,0,nRead); m c q!_#{y
} Y-vLEIX=
catch(Exception e){e.printStackTrace ();} KB6'sj
} Th%2pwvER
} ,R8:Y*@P
cZd{K[fuK
EKTn$k=
//打印回应的头信息 l:?w{'i$
public void logResponseHead(HttpURLConnection con) ),53(=/hl
{ O77bm,E
for(int i=1;;i++) E%tGwbi7
{ 6'YsSde".
String header=con.getHeaderFieldKey(i); yWkg4
if(header!=null) Wd78 bu|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0Xx&Z8E
Utility.log(header+" : "+con.getHeaderField(header)); 1GA$nFBVC
else XzV:q!e-
break; Tu*"+*r>s
} y)%CNH)*x
} =MCQNyf+
L%sskV(
6r3.%V.&
public void splitterStop() ,y%4QvG7a
{ hCvK2Xu
bStop = true; AIK99
} M,V~oc5
8a}et8df:
2$OI(7b=
} We51s^(
`<3xi9
L2GUrf
/* >3\($<YDZM
**FileAccess.java Iq%f*Zm<
*//文件访问(定位，写) g$P<`.
package NetFox; X4z6#S58
import java.io.*; \4qwLM?E^
S.Rqu+
q5D_bm7,3
public class FileAccessI implements Serializable{ njoU0f1`
ja1WI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fP:26pK^
RandomAccessFile oSavedFile; Eh{]so
long nPos; [@RJ2q$
]u\K}n6[q
)4@La&
public FileAccessI() throws IOException ZM$}Xy\9
{ p(J,fus
this("",0); >^\}"dEvr
} FdZG%N>Z
AR}q<k6E
n@ rphJb
public FileAccessI(String sName,long nPos) throws IOException Kq. MmR!gl
{ tOQura
oSavedFile = new RandomAccessFile(sName,"rw"); nm3/-Q},
this.nPos = nPos; O,>`#?
oSavedFile.seek(nPos); sh|@X\EZO
} L4wKG&
N9s ,..
_t+.I9kQ
public synchronized int write(byte[] b,int nStart,int nLen) Ev'BmDk
{ NjL^FqA[
int n = -1; afJ`1l
try{ R,'` A.Kk
oSavedFile.write(b,nStart,nLen); c(tX761qz
n = nLen; hrt]Qn&
} .JG>/+
catch(IOException e) n,.ZLuBEX
{ <l,Kg 'v
e.printStackTrace (); hj8S#
} /N'|Vs,X
uk\-"dS
4z$}e-
return n; O_n) 2t(c?
} @aX$}
ls<7Qe"a
SW^/\cJ^
} S@N:Cj
h9B^U?<wT
/M.@dW7 w
/* mnwYv..ePz
**SiteInfoBean.java b<N962 q$q
*/ +}u{{
package NetFox; IQz:DJ
.%iJin"
lM<SoC;[
public class SiteInfoBean { tBZ&h` V
Rp!R&U/
J#pl7q)^w
private String sSiteURL; //Site's URL U6R"eQUTV
private String sFilePath; //Saved File's Path `k>h2(@9S
private String sFileName; //Saved File's Name }.uB6&!:
private int nSplitter; //Count of Splited Downloading File H,F/u&O
\8I>^4t'/
#DL( %=:
public SiteInfoBean() ?Cu1"bl
{//nSplitter的缺省值为5 ^YpA@`n
//default value of nSplitter is 5 <}^W9>u<
this("","","",5); k>N >_{\
} J:{$\m'
TvEN0RV2
6__#n`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %/86}DCfE?
{ 5g{L -8XwI
sSiteURL= sURL; |Bv?! sjf
sFilePath = sPath; Or0eY#c
sFileName = sName; kg>Ymo.
this.nSplitter = nSpiltter; b :Knc$
k#4%d1O}
ON(H7
} 6Q&*V7EO
1-Fz#v7p
T@n-^B!Xq
public String getSSiteURL() <By6%<JTn
{ o4)^U t+
return sSiteURL; SX{shM2
} @aG1PG{
JY\8^}'9
Wp0e?bK_
public void setSSiteURL(String value) X[frL)k]
{ Q9lw~"
sSiteURL = value; CvCk#:@HM
} b6IYo!3
Su<Ggv"
^lqcF.
public String getSFilePath() =:+k
{ cT8`l!RD<
return sFilePath; @quNVx(y
} >uok\sX
?fog 34g
|(gq:O
public void setSFilePath(String value) _YXk,ME!Q
{ rz]0i@ehv'
sFilePath = value; *t;'I -1w^
} ;79X#hI
M DnT
_%@ri]u{ov
public String getSFileName() #McX
{ W{X5~w(
return sFileName; a_(fqoW
} XFi!=|F
p"|0PlW
7*(K%e"U
public void setSFileName(String value) hwi$:[
{ Q=?YY-*$
sFileName = value; J|@kF!6
} ~yu\vqN
W.7XShwd*2
;R*tT%Z,
public int getNSplitter() / TAza9a
{ b@ OF
return nSplitter; #<81`%
} Co^GsUJ
@WnW @'*F
HImQ.y!B
public void setNSplitter(int nCount) v@Bk)Z
{ Ry`Y +
nSplitter = nCount; l5<&pb#b
} G~{#%i
} ,Wlw#1fP
LDYk\[81
{(_>A\zi
/* @% .;}tC
**Utility.java u$ a7
*/ aB2t/ua
package NetFox; _\u?]YTv
Y~P* !g
*x@.$=NF"
public class Utility { 9PWqoz2c
Dz<vIMLF{
YjzGF=g#
public Utility() J9q[u[QZ9O
{ *B%ulsm
-jcgxQH53
>L,Pw1Y0W[
} ANlzF&K
0<u(!iL
//线程睡眠 8~:s$~&r
public static void sleep(int nSecond) _g%h:G&^
{ *5q_fO
try{ DNGj81'c
Thread.sleep(nSecond); ITf4PxF
} W7?f_E\>W
catch(Exception e) 04@?Jb1*
{ Ry"N_Fb
e.printStackTrace (); ?.6fVSa
} mM\jU5P:^
} %Z{ 7*jtE
aSQvtv)91
//日志 YV)h"u+@0
public static void log(String sMsg) c-=z<:Kf
{ /YD2F
System.err.println(sMsg); Z lR2
} <gjA(xT5
}<mK79m
~s-"u *>
public static void log(int sMsg) xF7q9'/F
{ ;Ff5ooL{
System.err.println(sMsg); z1m$8-4
} 6w*q~{"(
} }D*5PV%d
%-#rzeaW
on)$y&lu
/* ER)to<k
**TestMethod.java F.@U X{J
*/ _>(qQ-Px
package NetFox; &ngG_y8}&
!R3ZyZcX
Qcs>BOV~
public class TestMethod { 0/,Dy2h
?/FCq6o
w0YV87
public TestMethod() ]n^TN r7
{ ///xx/weblogic60b2_win.exe BiCC72oig
try{ "t:9jU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )~=g}&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l@<yC-Xd
SiteFileFetch fileFetch = new SiteFileFetch(bean); al{}p
fileFetch.start(); v>E3|w%
} prCr"y` M
catch(Exception e){e.printStackTrace ();} hp!. P1b
6*%E4#4
)sG/H8
} 2qe]1B;
6;%Ajx
!1fAW!8
public static void main(String[] args) O+*<^*YyD
{ VY_<c98v
new TestMethod(); xI,7ld~
} 6[SE*/E@L
} dBM> ;S;v
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