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)); |tkmO:
} F);C?SW"
for(int i=0;i<nEndPos.length-1;i++) b $!l*r
{ a+d|9y/k
nEndPos = nStartPos[i+1]; BL7%MvDQ
} Vj1AW<
nEndPos[nEndPos.length-1] = nFileLength; ?0F#\0
} mvnK)R_
} x.aUuC,$x
gKnAw+u\
_*_zyWW_j
//启动子线程 YN^8s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j"]%6RwM]
for(int i=0;i<nStartPos.length;i++) t+ @F"[j
{ 0Pe.G0 #
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j56Y,Tm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #&^+hx|
nStartPos,nEndPos,i); qH$p]+Rk 5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6+>rf{5P7
fileSplitterFetch.start(); ft5Bk'ZJ
} U]d+iz??b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6FfDif
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q~Ud>{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .%o:kq@B
nEndPos = " + nFileLength); NGxuwHIQ8
// fileSplitterFetch[nPos.length-1].start(); 8LOzL,Ah
DN+iS
/W;;7k
//等待子线程结束 tSjK=1"}
//int count = 0; p[RD[&#b
//是否结束while循环 [Z1EjeX
boolean breakWhile = false; t{ 'QMX
@#p4QEQA
;:cM^LJ
while(!bStop) X^?-Une
{ HO' HkVA
write_nPos(); 3WhJ,~o-y
Utility.sleep(500); W`KkuQ4cM
breakWhile = true; m{X;|-DK[
`7NgQ*g.d/
;YB8X&H$
for(int i=0;i<nStartPos.length;i++) 0xsvxH"*
{ S5;q)qz2J
if(!fileSplitterFetch.bDownOver) 3|C"F-'<
{ t]V)3Ww
breakWhile = false; RGcT
break; X6PfOep
} U6{ RHS[
} kG{(Qi
if(breakWhile) `g#\ Ws
break; E:7vm@+
dJkTHmw
:=* -x
//count++; 4h|D[Cb]
//if(count>4) R,(^fM
// siteStop(); 3.>jagu
} <1ai0]
HtMlSgx,8>
Z"P{/~HG
System.err.println("文件下载结束！"); @9^kl$
} v<O\ l~S
catch(Exception e){e.printStackTrace ();} ,5q^/h
} t ;[Me0
RD~QNj9,T
sQR;!-j
//获得文件长度 ;qvZ*
public long getFileSize() +ISB"a
{ Re=bJ|wo
int nFileLength = -1; 8s|r'
try{ ~_K
URL url = new URL(siteInfoBean.getSSiteURL()); 1Eg,iTn2*x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :D(:(`A=
httpConnection.setRequestProperty("User-Agent","NetFox"); gxJ(u{2
UHXlBH@
hcej?W8j
int responseCode=httpConnection.getResponseCode(); -WEiY
if(responseCode>=400) }L@YLnc%
{ E_$ST3
processErrorCode(responseCode); X!&=S!}
return -2; //-2 represent access is error ;DGp7f#9
} <F&S
p<Zf,F}
rq$%
String sHeader; |ek*wo
e&E*$G@.7
qWo|LpxWt
for(int i=1;;i++) b\}`L"
{ "|f;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e7<~[>g)
//Utility.log(in.readLine()); A=BpB}b
sHeader=httpConnection.getHeaderFieldKey(i); 9~a_^m/
if(sHeader!=null) ~]N% {;F}
{ -O2QzzE&
if(sHeader.equals("Content-Length")) X~lOFH;}q
{ guBOR0x`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [<cP~
break; YV0e)bf
} 4iDo.1B"
} m"u 9AOHk
else qD2<-E&M/
break; K?P.1H`
} %R(j|a9z
} #E>f.:)
catch(IOException e){e.printStackTrace ();} |i1z47jN6P
catch(Exception e){e.printStackTrace ();} 7GKeqv
u K 8r
w:pc5N>we0
Utility.log(nFileLength); NJn~XCq
=PXNg!B}D*
I_v]^>Xw
return nFileLength; 1298&C@
} /K'Kx
|Y:T3hra61
#[J..i/h
//保存下载信息（文件指针位置） AX[/S8|6
private void write_nPos() G>cTqD6gT
{ `lr\V;o!
try{ L{aT"Of{X
output = new DataOutputStream(new FileOutputStream(tmpFile)); }eBy p
output.writeInt(nStartPos.length); %Sj;:LC
for(int i=0;i<nStartPos.length;i++) T-JJc#
{ gm4-w 9M[p
// output.writeLong(nPos); :s*&_y
output.writeLong(fileSplitterFetch.nStartPos); 3"%:S_[
output.writeLong(fileSplitterFetch.nEndPos); 60-LpGhvy
} *_U z**M
output.close(); _)lK.5
} DAJh9I
catch(IOException e){e.printStackTrace ();} owQLAV
catch(Exception e){e.printStackTrace ();} 2Ask]
} -0lpsF
<PXA`]x~
g`\Vy4w
//读取保存的下载信息（文件指针位置） |qfnbi-\
private void read_nPos() D`iWf3a.
{ L[<MBgFKv
try{ SrU,-mA W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OpYq qBf_
int nCount = input.readInt(); @ -g^R4e<
nStartPos = new long[nCount]; *j8w" 4
nEndPos = new long[nCount]; 3 nb3rHQ
for(int i=0;i<nStartPos.length;i++) !i{@B
{ dA)7d77
nStartPos = input.readLong(); *F2obpU
nEndPos = input.readLong(); Z$Qlr:7
} #kk_iS>8
input.close(); \U p<m>3\
} I5PaY.i
catch(IOException e){e.printStackTrace ();} 5Gg`+o
catch(Exception e){e.printStackTrace ();} @zSoPDYv,
} H`m|R
%/s:G)
!j [U
private void processErrorCode(int nErrorCode) 3KP6M=
{ Yr!<O&=
System.err.println("Error Code : " + nErrorCode); vP?"MG
} }Li24JK
BB=%tz`B
%5jxq9:K
//停止文件下载 Ci=c"JdB
public void siteStop() IN),Lu0K
{ si0jXue~j\
bStop = true; XW`&1qx
for(int i=0;i<nStartPos.length;i++) ^i#F+Q`1
fileSplitterFetch.splitterStop(); QfRt3\^`
mLKwk6I
v:<u0B-)$
} j =[Td
} g7#_a6
//负责部分文件的抓取 ,!PNfJA2
**FileSplitterFetch.java 8V.x%T
*/ (8k3z`
package NetFox; >lN{FJ
r!#NFek}
ln#Lx&r;|
import java.io.*; A.*}<
import java.net.*; TE^BfAw@
xs+MvXTC
:!J!l u
public class FileSplitterFetch extends Thread { wQ@@|Cj4L
WRL &tz
rEz=\yY^j'
String sURL; //File URL W/xb[w9v
long nStartPos; //File Snippet Start Position X|@|ZRN
long nEndPos; //File Snippet End Position &nTB^MF
int nThreadID; //Thread's ID tJ[Hcx*N
boolean bDownOver = false; //Downing is over KGzBK:
boolean bStop = false; //Stop identical !&ac}uD^g
FileAccessI fileAccessI = null; //File Access interface M%sWtgw(
=M ?
tb^3-ZUb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XEY((VL0
{ o1-Zh!*a*
this.sURL = sURL; <JDkvpckx.
this.nStartPos = nStart; X{<j%PdC
this.nEndPos = nEnd; OV Iu&6#
nThreadID = id; a*KB'u6&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cPkN)+K
} \KDOI7
Z#nj[r!l}
bsR&%C
public void run() NA!;#!
{ D 0\
while(nStartPos < nEndPos && !bStop) )$i7b
{ VO/" ot
gfFP-J3cN
Skq%S`1%Q
try{ 2Cj?k.Zk
URL url = new URL(sURL); 6*{N{]`WZ)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }"2 0:
httpConnection.setRequestProperty("User-Agent","NetFox"); ,=R->~ J
String sProperty = "bytes="+nStartPos+"-"; %)?$82=2
httpConnection.setRequestProperty("RANGE",sProperty); VLkK6W.u
Utility.log(sProperty); 6ZR'1_i6i=
j ]F Zy
r[JgCj+$&
InputStream input = httpConnection.getInputStream(); {{SeD:hx
//logResponseHead(httpConnection); aB#qzrr['8
8lT.2H
WdnCRFO?l
byte[] b = new byte[1024]; %7z
int nRead; J}nE,U2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uJ{N?
{ V2V^*9(wu@
nStartPos += fileAccessI.write(b,0,nRead); nkSYW]aQ1g
//if(nThreadID == 1) q_ykB8Ensa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N?ky2wG
} q;InFV3rv
=VH, i/@
9Psy$
Utility.log("Thread " + nThreadID + " is over!"); w*f.Fu(su
bDownOver = true; $ GL$ iA
//nPos = fileAccessI.write (b,0,nRead); KaZ$!JfT
} P}KyT?X:
catch(Exception e){e.printStackTrace ();} 2~K.m@U}!Z
} K9;pX2^z9
} Sz.jv#Y
=pF 6
#,0%g1
//打印回应的头信息 a)`b;]+9
public void logResponseHead(HttpURLConnection con) 0' @^PzX
{ '/Hx0]V
for(int i=1;;i++) ix=HLF-0zC
{ @c9VCG D
String header=con.getHeaderFieldKey(i); ezY _7
if(header!=null) "'~'xaU!=a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JD^(L~n]
Utility.log(header+" : "+con.getHeaderField(header)); '@3hU|jO!
else Q!(C$&f
break; R]0awV1b
} e3yBB*@
} w<lHY=z E
3BDAvdJ4.
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public void splitterStop() EdhT;!
{ q1;}~}W;z4
bStop = true; I?.$
} 7xb z)FI
wyMj^+ 2m
QyuSle
} O\,n;oj
SYOND>E
l23_K7
/* /o*r[g7<
**FileAccess.java BHy#g>KUF
*//文件访问(定位，写) xVao3+r
package NetFox; #Wey)DI
import java.io.*; 3U!\5Nsby
Ig-9Y;hdmn
(A}##h
public class FileAccessI implements Serializable{ ;3s_#L
L 5J=+k,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /8VM.fr$
RandomAccessFile oSavedFile; wyzj[PDS
long nPos; Eb7qM.Q] &
l4I@6@
s/ibj@h
public FileAccessI() throws IOException ;\DXRKR
{ + G#qS1
this("",0); `7zz&f9dDX
} 6] <~0{
A% 9TS/-p
&B1d+.+
public FileAccessI(String sName,long nPos) throws IOException kL 6f^MoL
{ k6_RJ8I
oSavedFile = new RandomAccessFile(sName,"rw"); (%ra~s?
this.nPos = nPos; RY2`v pv
oSavedFile.seek(nPos); $?YRy_SI
} ~+d?d6*c
-x=abyD
,F`:4=H%
public synchronized int write(byte[] b,int nStart,int nLen) >:!TfuU^R
{ zM%ILv4
int n = -1; ?vuM'UH-
try{ v|C)Q %v
oSavedFile.write(b,nStart,nLen); ]1>U@oK
n = nLen; /-Y*V*E
} b*S:wfw
catch(IOException e) .9_]8T
{ Pou-AzEP$
e.printStackTrace (); T>2)YOx
} R,-y
3U9]&7^
?sWPx!tU
return n; F/sXr(7
} UKMr,{iy
B- =*"H?q
z1XFc*5
} p1 > D
h4N!zj[
JG @bl
/* 9`yG[OA
**SiteInfoBean.java s.&ewf\
*/ y Dg
package NetFox; gq~>S1
"vQ$RW -
Is&z~Xy/
public class SiteInfoBean { pMnkh}Q#
s1.YH?A;
% \p:S)R
private String sSiteURL; //Site's URL aRPgo0,W1
private String sFilePath; //Saved File's Path yb*P&si5bY
private String sFileName; //Saved File's Name ]`)50\pdw
private int nSplitter; //Count of Splited Downloading File Mk9'
pt.0%3
8gwJ%"-K
public SiteInfoBean() 5 fY\0
{//nSplitter的缺省值为5 JYB"\VV
//default value of nSplitter is 5 n=!]!'h\:
this("","","",5); Se/VOzzg
} Nv}'"V>
%SuEfCM
Q= IA|rN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6!7LgM%4
{ ~`)`Ip
sSiteURL= sURL; ZLw7-H6Fh
sFilePath = sPath; ovJ#2_
sFileName = sName; qXPjxTg{[
this.nSplitter = nSpiltter; gp'9Pf;\[
{E`[`Kf
OZ<iP
} \o3)\ e]o
9SF2
S\=j; Uem
public String getSSiteURL() 0; GnR0
{ j]th6
return sSiteURL; 5q?2?j/h
} >a7'_n_o
d\&{Ev9v
;BzbWvBo
public void setSSiteURL(String value) sUA==k
{ \|9@*]6:
sSiteURL = value; ) *Mr{`
} DZo7T!
Tbv", b
MTJ ."e<B
public String getSFilePath() L&V;Xvbu%
{ 'q%56WAJ
return sFilePath; T\7z87Q
} 2z9\p%MX
KW.*LoO
Sq^f}q
public void setSFilePath(String value) Za68V/Vj
{ GPBp.$q+B
sFilePath = value; 1OB,UU"S$
} a+A^njk
"FA&Qm0
4CA(` _i~
public String getSFileName() EC(,-sz\Z
{ Qvc "?yx8}
return sFileName; ?+#|h;M8
} A9Cq(L_H
W4n;U-Hb
Q72}V9I9
public void setSFileName(String value) fZ8%Z
{ k#mQLv
sFileName = value; mS?.xu
} V1y"
#[ZF'9x
1k-YeQNe
public int getNSplitter() VB 53n'
{ h'*>\eC6
return nSplitter; c@H_f
} ;',hwo_LBf
7{<:g!
#E35%7*
public void setNSplitter(int nCount) 5G5P#<Vv
{ zTA+s 2
nSplitter = nCount; &'%b1CbE
} 'a]4]d
} f#4,2Xf
Wp2b*B=-
['9awgkr/
/* Py^ _::
**Utility.java k?(x}IZdG
*/ yCznRd}J
package NetFox; 5=< y%VF
hf5yTs
2.''Nt6|
public class Utility { fL^+Qb}
>q W_%
c6 O1Z\M@\
public Utility() kmfz=q?
{ J<K-Yeph
<{$0mUn;s|
M#<U=Ha
} uZ[7[mK}n7
Djv0]Sm^!
//线程睡眠 iWCR5c=
public static void sleep(int nSecond) BS-nny
{ w[`2t{^j
try{ Po+I!TL'
Thread.sleep(nSecond); #<_gY
} sK1YmB :~a
catch(Exception e) oWCy%76@
{ -P I$SA,
e.printStackTrace (); Gyo[C98
} 66A}5b4)]
} _<;;CI3w
eN*=wOh
//日志 NBLiwL37{
public static void log(String sMsg) W lDcKY
{ m}t.E
System.err.println(sMsg); _8*}S=
} ~!PAs_O
)-2sk@y
9\2<#,R1q
public static void log(int sMsg) <5Ft3sd
{ U[l7n3Y=
System.err.println(sMsg); &G#LQl
} 3Z,J&d`[
} W6N3u7mrb
\BIa:}9O
x#wkODLqi
/* m8Wv46%
**TestMethod.java b=V"$(Q
*/ ,7` /D
package NetFox; !Q-h#']~L
VL^.7U
JCL+uEX4S
public class TestMethod { h6Femis
/(/Z~J[
d!BQ%a
public TestMethod() )Dg;W6
{ ///xx/weblogic60b2_win.exe .Vohd@s9l
try{ "nkj_pC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0Dx,)C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (#|CL/&
SiteFileFetch fileFetch = new SiteFileFetch(bean); f9+J}
fileFetch.start(); j41)X'MgJ
} M4%u~Z:4h+
catch(Exception e){e.printStackTrace ();} uc0 1{t0,
A`|Z2
s& INcjC
} X#625h
" Bz\<e&u
u%TZ),ny-
public static void main(String[] args) <F>^ffwGH-
{ Iq76JJuCb
new TestMethod(); hW^*b:v{
} 'hEvW
} VnZRsFY<^
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