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)); [d(@lbV0
} `zr%+
for(int i=0;i<nEndPos.length-1;i++) Ig9gGI,
{ UDJ{iZ
nEndPos = nStartPos[i+1]; aOS:rC
} (*.t~6c?5
nEndPos[nEndPos.length-1] = nFileLength; P/BWFN1
} j@JhxCe1+R
} 3GH@|id
a3&&7n
]et4B+=i
//启动子线程 <<43'N+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4LO U[D
for(int i=0;i<nStartPos.length;i++) dQ4VpR9|;
{ NWuJ&+gcO5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V3<baxdE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0!WF,)/T7i
nStartPos,nEndPos,i); 54TW8y `h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NVEjUt/
fileSplitterFetch.start(); EhEUkZE3)
} #WBlEVx;Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9y BENvq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MXSN <
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /Iwnl
nEndPos = " + nFileLength); gW{<:6}!*
// fileSplitterFetch[nPos.length-1].start(); OYw~I.Rq
d(.e%[`
L*k[Vc
//等待子线程结束 (!-gX"<b
//int count = 0; m).S0
//是否结束while循环 7 Jxhn!
boolean breakWhile = false; 8p4J7 -
7Ao9MF-
.ZuRH_pI
while(!bStop) l(-We.:(
{ `Yk~2t"V
write_nPos(); k lLhi<*
Utility.sleep(500); uFseO9F.2
breakWhile = true; Ekb9=/
m`"^d #
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for(int i=0;i<nStartPos.length;i++) /.Yf&2X\
{ hlY]s &0
if(!fileSplitterFetch.bDownOver) P5u Y1(
{ \8Mn[G9TL
breakWhile = false; ~U] "dbQ
break; 2TH13k$
} Tr}z&efY
} z >EOQe
if(breakWhile) (G:A^z
break; ^/nj2"
.hBq1p
RrFq"
//count++; \!!qzrq
//if(count>4) Bw;gl^:UG
// siteStop(); 9g*O;0uz
} cT2&nZ
(mO{W
)?5027^
System.err.println("文件下载结束！"); nz{ ;]U1
} LAe>XF-5
catch(Exception e){e.printStackTrace ();} )7$1Da|.
} `Aa}q(}k
}tq
`pMI@"m
//获得文件长度 B3x4sKs
public long getFileSize() gYeKeW3)
{ #'poDX?
int nFileLength = -1; -^1}J
try{ /_WAF90R?
URL url = new URL(siteInfoBean.getSSiteURL()); 3.i$lp`t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'eyzH[l,(
httpConnection.setRequestProperty("User-Agent","NetFox"); 2TFb!?/RQ
-L4fp
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int responseCode=httpConnection.getResponseCode(); ^Rr!YnEN
if(responseCode>=400) RIhu9W
{ mLEJt,X
processErrorCode(responseCode); ///
return -2; //-2 represent access is error a0wSXd
} sj9j47y
;jgk53lo
KT5amct
String sHeader; M~rN17S
ZmLA4<
jHPkfwfAF
for(int i=1;;i++) YC!IIE_
{ .Us)YVbk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {yo{@pdX>
//Utility.log(in.readLine()); Ow#a|@
sHeader=httpConnection.getHeaderFieldKey(i); :EGvI
if(sHeader!=null) *F<Ar\f5
{ ZVelKI8>
if(sHeader.equals("Content-Length")) JXx[e
{ ;[qA?<GJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &i(\g7%U
break; *VUD!`F
} Vn=K5nm
} e/7rr~"|
else w"Q/ 6#!K
break; x?"+Or.h
} T`zUgZ]
} [QwBSq8)
catch(IOException e){e.printStackTrace ();} \CU-a`n
catch(Exception e){e.printStackTrace ();} >Ut4INV
&Z3u(Eb
;i'mma_!
Utility.log(nFileLength); HZawB25{
^)nIf)9}7
g[c_rty
return nFileLength; kC_Kb&Q0
} YHp]O+c
Al MMN"j
DqJzsk'd3
//保存下载信息（文件指针位置） ,qK'!
private void write_nPos() eqY8;/
{ (rieg F
try{ uFUVcWt
output = new DataOutputStream(new FileOutputStream(tmpFile)); r}\m%(i
output.writeInt(nStartPos.length); W9rmAQjn
for(int i=0;i<nStartPos.length;i++) CJYpgSr
{ T;M4NGmvd
// output.writeLong(nPos); u|+Dqe`
output.writeLong(fileSplitterFetch.nStartPos); :!QT ,
output.writeLong(fileSplitterFetch.nEndPos); PL|ea~/
} 0woLB#v9
output.close(); h( DmSW
} Ln$= 8x^T
catch(IOException e){e.printStackTrace ();} [9C{\t
catch(Exception e){e.printStackTrace ();} Vv&GyqoO]
} e9;5.m
MP|$+yuR~
mhgvN-? "h
//读取保存的下载信息（文件指针位置） XY,!vLjL
private void read_nPos() s$Vz1B
{ sh/4ui{
try{ Y`*h#{|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C <d]0)
int nCount = input.readInt(); _Wtwh0[r*
nStartPos = new long[nCount]; 0TqIRUz "C
nEndPos = new long[nCount]; FL[,?RU?2
for(int i=0;i<nStartPos.length;i++) pS~=T}o
{ 9>6?tb"f*H
nStartPos = input.readLong(); Xd@ d$
nEndPos = input.readLong(); 7n[0)XR>
} J(5#fo{Q.g
input.close(); HP,{/ $i:
} XC!Y {lp
catch(IOException e){e.printStackTrace ();} !8I80:e_~
catch(Exception e){e.printStackTrace ();} W+i&!'
} 4vi[hiV
y[';@t7CC
eyuQ}R
private void processErrorCode(int nErrorCode) ! JauMR
{ 1oI2
System.err.println("Error Code : " + nErrorCode); ?h:xO\h8
} 6lm<>#_
w7~cY=
!>:]k?$b
//停止文件下载 ! Q8y]9O
public void siteStop() %-L T56T
{ m>f8RBp]'
bStop = true; o|APsQE
for(int i=0;i<nStartPos.length;i++) ,rX|_4n*
fileSplitterFetch.splitterStop(); n^Q-K}!T/
c#Qlr{ES
K?Jo"oy7
} L=gG23U&
} 'yR\%#s6
//负责部分文件的抓取 ?>NX}~2cf
**FileSplitterFetch.java _FkH;MGWS
*/ Yo\%53w/
package NetFox; 47)\\n_\z
$ncP#6
_QneaPm%
import java.io.*; a28`)17z
import java.net.*; NbK67p:
8{)N%r
p: u@? k
public class FileSplitterFetch extends Thread { ]f6,4[
y m?uj4I{
'26 ,.1
String sURL; //File URL /k KVIlO
long nStartPos; //File Snippet Start Position |=[._VH1
long nEndPos; //File Snippet End Position P:UR:y([
int nThreadID; //Thread's ID G[]h1f!
boolean bDownOver = false; //Downing is over bUe6f,8,
boolean bStop = false; //Stop identical 7 b{y
FileAccessI fileAccessI = null; //File Access interface 7 iQa)8,
s14ot80)
D2f~*!vEnA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u179!
{ 'M fVZho{
this.sURL = sURL; %?J-0
this.nStartPos = nStart; /d>Jkv
this.nEndPos = nEnd; 6%MM)Vj+u
nThreadID = id; #e[igxwi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m,Mg
} w$aejz`[
^xq)Q?[{
"Mh}n-oju
public void run() |N|[E5Cn
{ !T.yv5ge'
while(nStartPos < nEndPos && !bStop) db.~^][k
{ V]/$ dJ
=cI> {
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try{ WL;2&S/{@
URL url = new URL(sURL); vb$i00?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4+Y9":<
httpConnection.setRequestProperty("User-Agent","NetFox"); W{t-UK
String sProperty = "bytes="+nStartPos+"-"; B %
httpConnection.setRequestProperty("RANGE",sProperty); H<
Utility.log(sProperty); <W/YC2b
7|<-rjz^
;oOv~YB7H
InputStream input = httpConnection.getInputStream(); 1%7zCM0s
//logResponseHead(httpConnection); k;HI-v
Q@rlqWgU ~
>[g.8'hI
byte[] b = new byte[1024]; 7e Hj"_;
int nRead; \F<C$cys\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R.rE+gxO1
{ y27MG
nStartPos += fileAccessI.write(b,0,nRead); Zig3WiD&
//if(nThreadID == 1) @1V?94T1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !X1 KOG
} B \.05<
\j0016;
/brHB @$
Utility.log("Thread " + nThreadID + " is over!"); aL/7xa
bDownOver = true; d V3R)
//nPos = fileAccessI.write (b,0,nRead); P?zL`czWd
} X`7O%HiX/`
catch(Exception e){e.printStackTrace ();} 6\m'MV`R!
} 4TcW%
} )SfM`W)Y
UbP$WIrq
o'ZW
//打印回应的头信息 DK<}q1xi
public void logResponseHead(HttpURLConnection con) QLZ%m$Z
{ G.qjw]Llf
for(int i=1;;i++) 6}:(m#+
{ '3B7F5uLx"
String header=con.getHeaderFieldKey(i); P]4@|u;=6[
if(header!=null) U)SQ3*j2D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KXcE@q9
Utility.log(header+" : "+con.getHeaderField(header)); muKjeg'b
else 7qg. :h
break; Jg@eGs\*
} )NlxW5
} uC"Gm;0
.WlZT-
h[gKyxZ/t
public void splitterStop() wArzMt}[
{ bJL,pe+u
bStop = true; OmaG|2u
} "O%xQ N
8-)@q|
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} *4g:V;L
=]-D_$S~
m[A$Sp_"-h
/* 0;" >.
**FileAccess.java I_na^sh*
*//文件访问(定位，写) =]0AZ
package NetFox; nb(Od,L
import java.io.*; YF13&E2`\
6{2 9cX.
9j$J}=y
public class FileAccessI implements Serializable{ e;&fO[2
I(+%`{Wv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {Pe+d3Eoo
RandomAccessFile oSavedFile; g#[,4o;
long nPos; :JzJ(q/
qa5 T(:8
9w$+Qc
public FileAccessI() throws IOException n#)kvr
{ uG4Q\,R
this("",0); k E-+#p
} LS4E.Xdn
;V4f6[<]'z
6g'+1%O
public FileAccessI(String sName,long nPos) throws IOException ]PZ\N~T
{ ~Q5 i0s%
oSavedFile = new RandomAccessFile(sName,"rw"); VY "i>Ae
this.nPos = nPos; 0/zgjT|fe
oSavedFile.seek(nPos); {_]<mwd
} %s[ n2w
xMo'SpVz:
r<-@.$lf
public synchronized int write(byte[] b,int nStart,int nLen) )[5.*g@
{ k_7agW
int n = -1; a9TKp$LP`
try{ 2R`}}4<Z
oSavedFile.write(b,nStart,nLen); M}`G}*
n = nLen; t`vIcCXqyl
} };]f 3
catch(IOException e) 3H@29TrJ+
{ Iih]q
e.printStackTrace (); G:{\-R'
} fnudu0k
ftbOvG/ I
+AL(K:
return n; !!UQ,yU
} o'p[G]NQ1o
\k*h& :$
Bhw|!Y&%
} 7VAet
?K^~(D8(
1IV R4:a
/* ]LZ,>v
**SiteInfoBean.java ,SSq4
*/ Ems0"e
package NetFox; }A'Ro/n
P};GcV-
VNWa3`w
public class SiteInfoBean { Af7&;8pM
PU^@BZ_m
nwPU{4#l<
private String sSiteURL; //Site's URL xzTF| Z\
private String sFilePath; //Saved File's Path [49Ae2W`
private String sFileName; //Saved File's Name z7um9g
private int nSplitter; //Count of Splited Downloading File #dxS QmG
?<-ins
7.tEi}O&_g
public SiteInfoBean() ;B@-RfP
{//nSplitter的缺省值为5 :pPn)j$
//default value of nSplitter is 5 Hnc<)_DF
this("","","",5); ]~-vU{
} ]<?7CpP
"=\@ a=
k>q}: J9V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Gmp`3
{ m kHcGB!~
sSiteURL= sURL; ,?zOJ,wl
sFilePath = sPath; mY !LGN
sFileName = sName; om}jQJ]KH
this.nSplitter = nSpiltter; #Ez+1
;(,1pi7|
t`y*oRy
} `Aa*}1
u.Z,HsEOb
J}J7A5P
public String getSSiteURL() _F9O4Q4
{ hCKx%&[^7
return sSiteURL; ('VHL!
} =FtJa3mHK
sCE2 F_xjL
Z-B b,8
public void setSSiteURL(String value) zm('\KvT
{ '4}c1F1T_
sSiteURL = value; I~.d/!>Z
} ]J* y`jn
xRU ~hQ
O9tgS@*Tv
public String getSFilePath() Ee?+IZ H7|
{ }./_fFN@
return sFilePath; lSk<euCYs
} +|=5zWI/
I{0bsTp;
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public void setSFilePath(String value) @ dF]X
{ /P3s.-sL
sFilePath = value; HAr_z@#E
} p>@S61 & [
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mC}!;`$8p
public String getSFileName() 2og8VI
{ /NDuAjp[@
return sFileName; p!~{<s]
} ;y{VdT
J|BZ{T}d
ttK`*Ng
public void setSFileName(String value) Jqt&TqX@s
{ hIr$^%
sFileName = value; k-LT'>CWl
} &PAgab2$
.V\M/q\Tv
GK/Q]}Q8pZ
public int getNSplitter() u70-HFI@
{ *KXg;777
return nSplitter; Twj?SV
} l^IPN'O@
oYG].PC
9A4h?/
public void setNSplitter(int nCount) K~#wvUb
{ Q:x:k+O-
nSplitter = nCount; +HK)A%QI
} WSY&\8
} f2#9E+IQ
PZdYkbj
2z\4?HJy
/* GD$jP?
**Utility.java {xC CUU
*/ '1}rQqZ
package NetFox; B9Dh^9?L
/Jc?;@{
!vQ!_|g1
public class Utility { @J~y_J{
S%ri/}qI[{
Te8BFcJG
public Utility() FNDLqf!j
{ RTSR-<{z
%;0w2W
T$]2U>=<J
} 2.2Z'$W
W7as=+;X
//线程睡眠 +fhyw{
public static void sleep(int nSecond) k"SmbFn%N0
{ 0;)6ZU
try{ WRAW%?$
Thread.sleep(nSecond); V=|^r?
} `~(C\+gUp
catch(Exception e) ,h2q37
{ %uGA+ \b
e.printStackTrace (); B-[SUmHr
} Xl6)&
} &,Q{l$`X
[&*$!M
//日志 x 0
public static void log(String sMsg) F$ .j|C1a
{ K74oRKv
System.err.println(sMsg); ZZC= 7FB
} {I 7pk6Qd
Hcd>\0
](0Vm_es
public static void log(int sMsg) A!k}
{ ud:?~?j&w
System.err.println(sMsg); ~~1~_0?e
} ~rCnST
} 9L#B"lh
+>qBK}`
z K8#gif@
/* ):78GVp
**TestMethod.java M{kPEl&Z
*/ CHpDzG>]4
package NetFox; >2syF{`j
wHZ!t,g
hqD;<:.
public class TestMethod { Vd<= y
0HD1Ob^@
pjj 5
public TestMethod() Ql*/{#$
{ ///xx/weblogic60b2_win.exe $fKwJFr
try{ 0v7;ZxD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w78Ius,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?XOeMI
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z `\7B e
fileFetch.start(); P)ZSxU
} S,(@Q~
catch(Exception e){e.printStackTrace ();} [!R%yD;
x>8f#B\Mr
,IJNuu\
} ^Js9E
)ql?}
<Ab:yD`K!
public static void main(String[] args) : m5u=:t
{ rFy9K4D
new TestMethod(); [d&Faa[`
} c&Zm>Qo[
} ABHZ)OM
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