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)); ;{C{V{
} ^cXL4*_=
for(int i=0;i<nEndPos.length-1;i++) >Ti2E+}[M
{ s7cyo ]
nEndPos = nStartPos[i+1]; w0`L)f5v
} .L|ax).D
nEndPos[nEndPos.length-1] = nFileLength; (dprY1noC
} P!&CH4+
} tcdn"]#U
@tp7tB ;
_+Kt=;Y8
//启动子线程 .7^-*HT}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y>m=cqR
for(int i=0;i<nStartPos.length;i++) Tsp-]-)
{ P+|8MT0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y!D`.'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "$V2$
nStartPos,nEndPos,i); 2cL)sP}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M HB]'
fileSplitterFetch.start(); NS~knR\&
} RL)3k8pk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UN4)>\Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 491I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #C7j|9Ew1]
nEndPos = " + nFileLength); PGhZ`nl
// fileSplitterFetch[nPos.length-1].start(); #E@i@'T
vj$6
+E[)@;T
//等待子线程结束 ABDUp:
//int count = 0; m =F@CA~C
//是否结束while循环 0>MI*fnY"
boolean breakWhile = false; zQ+t@;g1
F}DD;K
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while(!bStop) ck+rOGv7{Z
{ O;sQPG,v
write_nPos(); .4(f0RG
Utility.sleep(500); p>O< "X@
breakWhile = true; o+Z9h1z%,
"uC*B4`
D.!7jA#
for(int i=0;i<nStartPos.length;i++) ]*U')
{ =Q/>g6
if(!fileSplitterFetch.bDownOver) X5<.%@Z
{ 9Dw&b
breakWhile = false; XOU$3+8q5
break; $3B?
} ,4,c-
} &/?jMyD@
if(breakWhile) Acv{XnB
break; elB 8
l$9,
:L0W"$
//count++; @/FX7O{n:
//if(count>4) `%p6i| _Q
// siteStop(); W2N7
} j #YFwX4.
%MNV 5UA[w
-P&e4sV{
System.err.println("文件下载结束！"); qQvb;jO
} Y sV
catch(Exception e){e.printStackTrace ();} )&Bv\Tfjt
} 0&@pX~h:
,2bAKa
CF_!{X_k}
//获得文件长度 3fTI&2:
public long getFileSize() 3kY4V*9@-
{ KK$A4`YoR
int nFileLength = -1; yFsXI0I[p
try{ {Z.@-Tl_
URL url = new URL(siteInfoBean.getSSiteURL()); q(Q9FonU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e`F|sz]k"H
httpConnection.setRequestProperty("User-Agent","NetFox"); eUlb6{!y?
1+($"$ZC&B
id'#s
int responseCode=httpConnection.getResponseCode(); E2D8s=r
if(responseCode>=400) ~#\#!H7
{ O%e.u>=4%
processErrorCode(responseCode); =:eE!
return -2; //-2 represent access is error =i?,y+<
} ^j}sS!p
KW^aARJ)
gQ#T7
String sHeader; wP?q5r5
K~T\q_ZPZ
[{$0E=&0
for(int i=1;;i++) :`1g{8.+
{ k1zt|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f@L{*Upj+
//Utility.log(in.readLine()); TVwYFX
sHeader=httpConnection.getHeaderFieldKey(i); ^MV%\0o
if(sHeader!=null) ]i2\2MTW8
{ IxBO$2
if(sHeader.equals("Content-Length")) |3ETF|)?
{ _Qc\v0%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }* JMc+!9@
break; _1Gut"!{\
} S\gP=.G
} e8<nPt`C
else Ct+%
break; va2A@U
} A"iD4Q
} RQNi&zX/
catch(IOException e){e.printStackTrace ();} REBDr;tv
catch(Exception e){e.printStackTrace ();} 'fFdqsXr
1:UC\WW
~')t1Ays
Utility.log(nFileLength); >Fk`h=Wd
^VPl>jTg
l?_!eA
return nFileLength; m-92G8'
} 6*33k'=;F
CT%m_lN
[qMdOY%jx
//保存下载信息（文件指针位置） ?u!AHSr(
private void write_nPos() %v:h]TA
{ ^QR'yt3e
try{ W+C_=7_
output = new DataOutputStream(new FileOutputStream(tmpFile)); }h h^U^ia
output.writeInt(nStartPos.length); $50"3g!Y
for(int i=0;i<nStartPos.length;i++) <dPxy`_
{ ~c$ts&Cl
// output.writeLong(nPos); Jd"s~n<>K
output.writeLong(fileSplitterFetch.nStartPos); F>(#Af9
output.writeLong(fileSplitterFetch.nEndPos); 166c\QO
} o 0ivja
output.close(); vD9D:vK
} QF/u^|f
catch(IOException e){e.printStackTrace ();} ^6y4!='ci
catch(Exception e){e.printStackTrace ();} G5y
} AeCG2!8^0
m{dyVE
,T*_mDVY
//读取保存的下载信息（文件指针位置） "`*a)'.'^c
private void read_nPos() (,c?}TP
{ W)msaq,
try{ $"{3yLg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *?EO n-
int nCount = input.readInt(); T@%;0Ro~
nStartPos = new long[nCount]; LvSP #$f
nEndPos = new long[nCount]; 0@II&
for(int i=0;i<nStartPos.length;i++) }f<fgY
{ A2}Z *U(;
nStartPos = input.readLong(); NvQY7C
nEndPos = input.readLong(); fR+Ov8PCq
} qf_hb
input.close(); 9 Q0#We*
} #[gcg]6c
catch(IOException e){e.printStackTrace ();} +^/Nil
catch(Exception e){e.printStackTrace ();} VQ1?Db(_2
} z*Myokhf
[z W_%O kP
XR{5]lKt_
private void processErrorCode(int nErrorCode) dH ^b)G4
{ ZcUh[5:|
System.err.println("Error Code : " + nErrorCode); Paae-EmC
} pb=jvK
o|rGy5
t!J";l
//停止文件下载 s[0prm5.
public void siteStop() <7vIh0
{ Ma`
bStop = true; S(g<<Te
for(int i=0;i<nStartPos.length;i++) 4@/q_*3o
fileSplitterFetch.splitterStop(); 0C7thl{Dms
a}5vY
OhSt6&+
} <Z\MZ&{k{*
} u\Nw:Uu i
//负责部分文件的抓取 Ff)~clIK '
**FileSplitterFetch.java 'DL;c@}37
*/ qB+:#Yrx/
package NetFox; q;1VF;<"vH
+XU$GSw3(
t7U,AQ=;P5
import java.io.*; "}]GQt< F
import java.net.*; J9b?}-O)
7|h3.
oW yN:Qh
public class FileSplitterFetch extends Thread { 1+16i=BF)
^Ff~j&L@{
Ux%\Y.PPI
String sURL; //File URL ;JPbBwm
long nStartPos; //File Snippet Start Position ,p[\fT($]
long nEndPos; //File Snippet End Position C*W.9
int nThreadID; //Thread's ID )$gsU@H -
boolean bDownOver = false; //Downing is over C$AIP\j- )
boolean bStop = false; //Stop identical 4'}_qAT
FileAccessI fileAccessI = null; //File Access interface Pv{,aV\I}
&9RW9u "
J^s<x#C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wB1|r{
{ K-"HcHuF
this.sURL = sURL; t[f9Z
this.nStartPos = nStart; \V"PmaP\
this.nEndPos = nEnd; RF,=bOr19
nThreadID = id; S2At$47v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V(''p{
} '1kj:Np
FkJ>]k
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public void run() %/6e"o
{ vs'L1$L'c
while(nStartPos < nEndPos && !bStop) 9GtVI^]
{ bzj!d|T`
MoKXl?B<
7&RJDa:a7T
try{ "j.oR}s9?#
URL url = new URL(sURL); v'bd.eqw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p~d)2TC4#
httpConnection.setRequestProperty("User-Agent","NetFox"); >jrz;r
String sProperty = "bytes="+nStartPos+"-"; -u3SsU)_%N
httpConnection.setRequestProperty("RANGE",sProperty); ~*cY& 9
Utility.log(sProperty); y 8d`},
@E"+qPp.3
y_7XYT!w
InputStream input = httpConnection.getInputStream(); :)J~FVLy
//logResponseHead(httpConnection); ~Q$c!=
_OknP2E
xV n]m9i
byte[] b = new byte[1024]; 1n"+~N^\
int nRead; qK6 uU9z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ev;5?9\E
{ [Tb3z:UUvf
nStartPos += fileAccessI.write(b,0,nRead); ZoNNM4M+
//if(nThreadID == 1) uZ2v;]\Y6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G|PIH#
} )ejXeg
9h,yb4jPP
/P8eI3R
Utility.log("Thread " + nThreadID + " is over!"); vu.S>2Wv
bDownOver = true; [@. jL0>
//nPos = fileAccessI.write (b,0,nRead); Ng;b!S
} Am=PUQF$
catch(Exception e){e.printStackTrace ();} YI),q.3X~
} sei!9+bZr
} Uhx2 _
A^Hp#b@
AFm*60C
//打印回应的头信息 seD+~Y\z
public void logResponseHead(HttpURLConnection con) >A'!T'"~
{ Dgq[g_+l
for(int i=1;;i++) |z7Crz
{ EPd.atA
String header=con.getHeaderFieldKey(i); _Fh0^O@
if(header!=null) 8JFkeU%yO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _]r)6RT
Utility.log(header+" : "+con.getHeaderField(header)); M"$RtS|h
else gmAKW4(
break; 7E6?)bgh
} J0WXH/:
} k;:u| s8NS
W4rw;(\
Z%n.:I<%ZV
public void splitterStop() \7tvNa,C
{ }9Dv\"t5
bStop = true; o(SJuZC/U
} UCj#t!Mw
gMK3o8B/
-K'84 bZ
} .idl@%
xo 'w+Av
NCM{OAjS5U
/* ;o@`l$O
**FileAccess.java leYmVFE
*//文件访问(定位，写) Joo)GIB
package NetFox; +p}Xmn
import java.io.*; eD1MP<>h
>]|^Ux,WZ
K$vRk5U
public class FileAccessI implements Serializable{ Pk]9.e1_
!<PTsk F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,v5>sL
RandomAccessFile oSavedFile; MmX[xk
long nPos; +~{nU'
-Izg&u &
d@4=XSj
public FileAccessI() throws IOException 4_:e+ ql
{ W2(=m!:U
this("",0); )3\rp$]1
} XUNgt(OGR'
R#bV/7Ol
^g){)rz|
public FileAccessI(String sName,long nPos) throws IOException uOUw8
{ !3M!p&
oSavedFile = new RandomAccessFile(sName,"rw"); n?fC_dy
this.nPos = nPos; 4i&!V9@:
oSavedFile.seek(nPos); C4TD@
} (xJBN?NRO
&|FG#.2yw
G%/cV?18
public synchronized int write(byte[] b,int nStart,int nLen) pnb$lpxt
{ / ^M3-5@Q
int n = -1; u}0t`w:
try{ JkEQ@x
oSavedFile.write(b,nStart,nLen); +mPB?5
n = nLen; ]= D
} iv`-)UsE
catch(IOException e) l{{ #tW
{ bbA<Zp
e.printStackTrace (); mM~Q!`Nf.
} ;G&O"S><]c
Y{{,62D
`b$I)UUm
return n; KiHAm|,
} !aoO,P#j
%['F[Mo
j+v)I=
} :{imRa-
A[Xw|9
49>yIuG
/* "q8'tN><
**SiteInfoBean.java ]sIFK
*/ }trMQ
package NetFox; \EqO;A%<
!2,.C+,
I!%@|[ Ow
public class SiteInfoBean { S+ x[1#r
o W [-?
XiUsaoQm3
private String sSiteURL; //Site's URL L>*|T[~
private String sFilePath; //Saved File's Path ttxOP
private String sFileName; //Saved File's Name HKf3eC
private int nSplitter; //Count of Splited Downloading File R``qQ;cc
?/g(Y
*9 xD]ZZF
public SiteInfoBean() r4'Pf|`u
{//nSplitter的缺省值为5 8Aqe'2IH=
//default value of nSplitter is 5 D-/A>
this("","","",5); Y"U&3e,
} jk?(W2c#{
dWEx55>,1
\>Q,AyL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F.6SX (x
{ vOU-bF%u
sSiteURL= sURL; 6y5~Kh6
sFilePath = sPath; 3H2'HO
sFileName = sName; g.qp _O
this.nSplitter = nSpiltter; gfHlY Q]
7KLq-u-8
3Hr%G4
} qxNV~aK
%r!-*p<i|
ud1E@4;qf
public String getSSiteURL() #k6T_ki
{ bT |FJ\aC
return sSiteURL; h&P[9:LH
} 1>LquZ+Kj
Spb'jAKj'
YrX{,YtiX
public void setSSiteURL(String value) \ U_DTI
{ A}o1I1+
sSiteURL = value; 5Dd;?T>
} F$v G=3
] N8V?.|:
y[# U/2
public String getSFilePath() b?l\QMvi
{ G}g+2`
return sFilePath; pbNVj~#6
} X|:O`b$G
TqC"lO>:Q
E6uIp^E
public void setSFilePath(String value) YR>xh2< 9
{ 5 X rn]
sFilePath = value; G!uxpZ
} H'0S;A+Y6
kK(,FB
W#$rC<Jh]
public String getSFileName() Ogb!YF#e
{ sSxra!tv4
return sFileName; *@< jJP4
} ;)*Drk*t,
z]pH'c39
.nnAI@7E
public void setSFileName(String value) mOBS[M5*
{ #Uo 9BM
sFileName = value; 7_LE2jpC,5
} %~@}wHMB
>:.Bn8-
*l}q,9iQ-
public int getNSplitter() KpWQ;3D2
{ D0~mu{;c$
return nSplitter; s;L7 _.hH@
} DLVf7/=3~
Ha<(~qf
ey:3F%
public void setNSplitter(int nCount) cP-6O42
{ +%0+
nSplitter = nCount; ~<aCn-h0
} ~FJd{$2x`
} >R6Me*VR
B<W{kEY
hTF]-& hZ
/* ^z_~e@U
**Utility.java yzYPT}t
*/ l+@NjZGm<
package NetFox; 3K{'~?mM
EBJaFz'
2$|WXYY
public class Utility { 0-7xcF@s
RszqDm
Rv }e+5F
public Utility() A@GyKx%x$
{ 4Vh#Ye:`
V^"5cW
r@ ]{`qA
} YOqBIbp~&)
&R25J$
//线程睡眠 Y~,N,>nITu
public static void sleep(int nSecond) hH>t
{ VCtj8hKDr
try{ v. !L:1@I.
Thread.sleep(nSecond); R'He(x
} PXWBc\
catch(Exception e) N|wI=To
{ oQAD 3a
e.printStackTrace (); cZi/bIh
} W2s6!_AN
} ?FJU>+{">
a=Pl3Uo
//日志 ;BsyN[bF
public static void log(String sMsg) }<m9w\pA
{ i.Yz)Bw
System.err.println(sMsg); Cjdw@v0;
} N"Q-xK
u.43b8!
Y<odXFIS
public static void log(int sMsg) <7-3j{065
{ yalT6
System.err.println(sMsg); :@mb.'%*!
} v25]}9/C
} N$i!25F`
Tc$Jvy-G4A
B*W)e$
/* <'f+nC=2
**TestMethod.java `ZhDoLpH<
*/ jInI%
package NetFox; 9l<f?OzAO
R<}UT
_HjS!(lMk
public class TestMethod { KPTp91
_P,3~ ;
F|nJ3:v
public TestMethod() UaG })
{ ///xx/weblogic60b2_win.exe 3 vr T`
try{ cHP~J%&L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vuN!7*d+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ls51U7
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2z#gn9Wb
fileFetch.start(); $IUe](a{d
} K FMx(fD
catch(Exception e){e.printStackTrace ();} "0Ca;hSLM2
rs`"Kz`(
)/Z% HBn
} [ H|ifi
qGivRDR$
|&wwH&<[z
public static void main(String[] args) }*Z *wC
{ ~IQ3B$4H&
new TestMethod(); `YL)[t? V
} 9IfeaoZZ4q
} T*pcS'?'
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