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)); [RY Rt/?Q
} =K_&@|f+B
for(int i=0;i<nEndPos.length-1;i++) |*DkriYY
{ lF t^dl^
nEndPos = nStartPos[i+1]; PEg]z
} FmFjRYA W
nEndPos[nEndPos.length-1] = nFileLength; 'Yi="kno
} W23Q>x&S
} Te`@{>
[jksOC)@4
9s*QHCB0
//启动子线程 TY%=Y=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B3pjli
for(int i=0;i<nStartPos.length;i++) _zJ /z
{ _90<*{bt.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `<kB/T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O8cZl1C3
nStartPos,nEndPos,i); @|5B}%!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ioEjbqD<
fileSplitterFetch.start(); ?^2nrh,n+
} &er,Wyc(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y`(~eNX^%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 97qf3^gGd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m'N8[ o|h
nEndPos = " + nFileLength); wa~zb!y<
// fileSplitterFetch[nPos.length-1].start(); (#Xs\IEVF
=z]rZSq*o
&H P g>
//等待子线程结束 t2YB(6w+xg
//int count = 0; gVe]?Jva`
//是否结束while循环 t\}_WygN
boolean breakWhile = false; <EQaYZY=
z;y{QO
(z8;J>7
while(!bStop) R7K`9 c1f6
{ I~^Xw7
write_nPos(); !XM<`H/
Utility.sleep(500); uE<8L(*B
breakWhile = true; ( mn:!3H%
00{a}@n
gwdAf%|f
for(int i=0;i<nStartPos.length;i++) Pouo# 5
{ 1)jeawVmj
if(!fileSplitterFetch.bDownOver) N&eo;Ti
{ _RUL$Ds
breakWhile = false; `6lOqH
break; ^G2M4+W|
} SM%/pu;
} ' Ttsscv
if(breakWhile) 3l,-n|x
break; S;jD@j\t&
tv`b##
1X7GM65#
//count++; tC(MaI
//if(count>4) p2k`)=iX
// siteStop(); jvAjnh#
} ;]b4O4C\
DA04llX~
5!cp^[rGL
System.err.println("文件下载结束！"); -FI)o`AE
} lC`w}0p
catch(Exception e){e.printStackTrace ();} r>7+&s*yk
} $(+xhn(O
dJ/gc"7aO
1KbZ6Msy
//获得文件长度 S,ea[$_
public long getFileSize() MBU|<tc
{ ;']u}Nh
int nFileLength = -1; -*Rf [|Z
try{ .@%L8_sMR
URL url = new URL(siteInfoBean.getSSiteURL()); v|\#wrCT?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fQ~TZ:UrU
httpConnection.setRequestProperty("User-Agent","NetFox"); TnKv)%VF
UP$>,05z6
L6DYunh}^N
int responseCode=httpConnection.getResponseCode(); k52IvB@2
if(responseCode>=400) MmfBFt*
{ #ACT&J
processErrorCode(responseCode); sW'_K.z
return -2; //-2 represent access is error EI7n|X a1q
} [3s-S+n @
p5tb=Zg_
(QL:7
String sHeader; S9]I[4
'S9o!hb'@
f6yj\qq]
for(int i=1;;i++) ]s\vc:cc?
{ c61OT@dZEA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Yj*T'<e
//Utility.log(in.readLine()); ~CbiKez
sHeader=httpConnection.getHeaderFieldKey(i); ^<-)rzTI
if(sHeader!=null) 2O*At%CzW
{ 6W{Nw<
if(sHeader.equals("Content-Length")) +Ugy=678Tr
{ > Xh=P%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rab$[?]
break; 4w=v /WDo
} fM7B<eB
} sve} ent
else /3Gq&[R{
break; ZOcpF1y
} m_CWVw
} 8<mloM-4
catch(IOException e){e.printStackTrace ();} YY:{/0?
catch(Exception e){e.printStackTrace ();} 9#:fQ!3`
+_$s9`@]6
xw_klHL-o
Utility.log(nFileLength); R9 Ab.t
]Idwy|eG
\8!CKnfs
return nFileLength; {U$XHG
} R]e&JoY
A[^#8evaK
dor1(@no|
//保存下载信息（文件指针位置） k ,ldi
private void write_nPos() G+Z ,ic
{ ,Yx<"2 W
try{ $[?N^
output = new DataOutputStream(new FileOutputStream(tmpFile)); /<n7iIK)
output.writeInt(nStartPos.length); M>Tg$^lm
for(int i=0;i<nStartPos.length;i++) }2LWDQ;po
{ %&&)[
// output.writeLong(nPos); Y'~O_coG
output.writeLong(fileSplitterFetch.nStartPos); !j`<iPI7B
output.writeLong(fileSplitterFetch.nEndPos); Khi;2{`
} m(MQ
output.close(); 5,##p"O(
} -dO8Uis$
catch(IOException e){e.printStackTrace ();} IqFcrU$4
catch(Exception e){e.printStackTrace ();} 2t_g\Q
} "{qnm+G
"qF/7`e[
\%Y`>x.
//读取保存的下载信息（文件指针位置） NQ;X|$!zH
private void read_nPos() 97\K]Tr
{ p7-\a1P3
try{ ]r3/hDRDL@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qs za,09
int nCount = input.readInt(); Y:O|6%00Y
nStartPos = new long[nCount]; %a WRXW@c
nEndPos = new long[nCount]; K mH))LIv
for(int i=0;i<nStartPos.length;i++) 9xz@2b@
{ *cCx]C.~
nStartPos = input.readLong(); j3;W-c`5
nEndPos = input.readLong(); &U?4e'N)T
} Z8FgxR
input.close(); f~\H|E8(
} w^ z ftm
catch(IOException e){e.printStackTrace ();} @(35I
catch(Exception e){e.printStackTrace ();} r>ed/<_>m;
} 9v`sSTlSd
$;G<!]& s
He'VqUw_
private void processErrorCode(int nErrorCode) Jh=.}FXnjL
{ l$\B>u,>
System.err.println("Error Code : " + nErrorCode); qhvT,"
} 3{|~'5*
p*42 @1,
,(Zxd4?y
//停止文件下载 HQ9tvSc
public void siteStop() 2"Wq=qy\J
{ {g1"{
bStop = true; VFZ?<m
for(int i=0;i<nStartPos.length;i++) ,M?8s2?
fileSplitterFetch.splitterStop(); 9%|skTgIqH
^ '|y^t
LH_H yP_
} (>A#|N1U
} [(_,\:L${
//负责部分文件的抓取 ,)*[Xa_n
**FileSplitterFetch.java )uOtQ0
*/ PkyX,mr#1
package NetFox; i&lW&]
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KCbJ^Rln
import java.io.*; >'q]ypA1
import java.net.*; L-E?1qhP>
Z3c\}HLY
_[z)%`kay
public class FileSplitterFetch extends Thread { ~K#92
s<#BxN
O&aD]~|
String sURL; //File URL rn( drG
long nStartPos; //File Snippet Start Position HP_h!pvx
long nEndPos; //File Snippet End Position )e'F[
int nThreadID; //Thread's ID #z&R9$
boolean bDownOver = false; //Downing is over ^`lrKk
boolean bStop = false; //Stop identical }JST(d&
FileAccessI fileAccessI = null; //File Access interface TA/hj>rV
b3[[ Ah-
[Z2[Iy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j0+D99{R
{ e#k rr
this.sURL = sURL; ]zyT_}&
this.nStartPos = nStart; AN:s%w2
this.nEndPos = nEnd; "IQYy~ /
nThreadID = id; >SvS(N{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 IoJI|lP
} .wq j
(nmsw6 X
8g)$%Fy+N
public void run() zF^H*H
{ D=z="p\
while(nStartPos < nEndPos && !bStop) ]!sCWR
{ 6?%$e$s
]!^wB 3j
"@^<~bw
try{ +,YK}?e
URL url = new URL(sURL); NY<qoV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ktynIN
httpConnection.setRequestProperty("User-Agent","NetFox"); am3.Dt2\
String sProperty = "bytes="+nStartPos+"-"; h>*3i#
httpConnection.setRequestProperty("RANGE",sProperty); 3GKKC9C6
Utility.log(sProperty); xLFMC?I
K]B`&ih
!ck~4~J
InputStream input = httpConnection.getInputStream(); D:j5/ *
//logResponseHead(httpConnection); R'tvF$3=i
w=!xTA
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byte[] b = new byte[1024]; l3^'bp6HQ
int nRead; 0iM'),v[]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^ op0" #B
{ cy!P!t,@
nStartPos += fileAccessI.write(b,0,nRead); &L?]w=*
//if(nThreadID == 1) eP:\\; ;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l$j~p=S$F
} X6Z/xb@
g|| q 3
cE`qfz
Utility.log("Thread " + nThreadID + " is over!"); YKU|D32
bDownOver = true; $-pijBiz_
//nPos = fileAccessI.write (b,0,nRead); x2&5zp
} +924_,zF
catch(Exception e){e.printStackTrace ();} "2-D[rYZ
} Z]{=Jy!F
} mDp8JNJNE
{g[kn^|
ndDF(qHr
//打印回应的头信息 "AXgT[ O
public void logResponseHead(HttpURLConnection con) G#`
{ fW=<bf
for(int i=1;;i++) >)NS U
{ 'L7u`
String header=con.getHeaderFieldKey(i); @N<h`vDa
if(header!=null) dQrz+_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;AVIt!(L~V
Utility.log(header+" : "+con.getHeaderField(header)); LU8[$.P
else tMP"9JE,
break; Oh10X.)i
} o-&0_Zq_
} YR/I<m`]}
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(U$;0`
public void splitterStop() 2{BS `f
{ )sK53O$
bStop = true; x;:jF_
} ]G8"\J4 &
F?FfRzZ[
EQpF:@_
} AFBWiuwI3
fD\Fq'29{
J[uH@3v
/* N}#"o
**FileAccess.java icIWv
*//文件访问(定位，写) C .B=E"e
package NetFox; x)eF{%QB
import java.io.*; =a+ } 6
F/LMk8RgR
fyT|xI`iD
public class FileAccessI implements Serializable{ b|E ZD3y
[FF}HWf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nTtEv~a_n
RandomAccessFile oSavedFile; :EYUBtTj
long nPos; n!SHExBp
*]R5bj.!o
`Xeiz'~f8
public FileAccessI() throws IOException =E!Y f#p+q
{ cl4_M{~
this("",0); 8_Uhh5[
} m:0[as=
3'i(wI~<[
%LmsywPPp
public FileAccessI(String sName,long nPos) throws IOException -w"lW7
{ :r "GZ
oSavedFile = new RandomAccessFile(sName,"rw"); ;-"q;&1e
this.nPos = nPos; [lSQMoi3
oSavedFile.seek(nPos); fdwP@6eh
} +G"YQq'b
|w#~v%w
QT!>izgcU
public synchronized int write(byte[] b,int nStart,int nLen) +C,/BuG
{ :HrFbq
int n = -1; &\cS{35
try{ /joY? T
oSavedFile.write(b,nStart,nLen); nnT#S
n = nLen; a%kvC#B
} h*1T3U$
catch(IOException e) R)SY#*Y
{ l.g.O>1
e.printStackTrace (); 0nkC%j
} )'RaMo` 4
y4IQa.F
j6k"%QHf
return n; uH'?Ikx"
} 8L_OH
:IJ<Mmb
xz.M'az\
} 1+7_L`SB
0&Ftx%6%
3< 6h~ek)
/* 6:; >id${
**SiteInfoBean.java LCj3{>{/=
*/ /5L\:eX%
package NetFox; gzat!>*
Qmo}esb'(
#QcRN?s
public class SiteInfoBean { GRofOJ
jgPUR#)
MXEI/mDYK
private String sSiteURL; //Site's URL T=sAy/1oR
private String sFilePath; //Saved File's Path `T1bY9O.
private String sFileName; //Saved File's Name =6=:OId
private int nSplitter; //Count of Splited Downloading File 's5rl
~QPTs1Vk8
-Hw3rv3o
public SiteInfoBean() gdqBT]j
{//nSplitter的缺省值为5 ]yqE6Lf9
//default value of nSplitter is 5 BaIuOZ@,
this("","","",5); s]kzXzRC?
} c[ 0`8s!
+U_1B%e(%
8>x'. 8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L1g0Dd\Ox
{ bE2O[B
sSiteURL= sURL; NR8`nc1~
sFilePath = sPath; ZADMtsk
sFileName = sName; ZS]Z0iZv9
this.nSplitter = nSpiltter; a:HN#P)12
mDbTOtD
z9OpxW@Ou
} >!']w{G
z^&$6c_
Tl[*(|/C
public String getSSiteURL() f#GMJ mCQs
{ hjFht+j1
return sSiteURL; <`; {gX1
} f$-n%7
55$';gh,9
mF+8Q
public void setSSiteURL(String value) !V/\_P!I
{ x@bqPZ t
sSiteURL = value; oZ tCx
} whHuV*K}
N#e9w3Rli
Rj>A",
public String getSFilePath() aD'Ax\-
{ u'_}4qhCC;
return sFilePath; VzHrKI
} C3f\E: D)
Mb\(52`)Q
xypgG;`\
public void setSFilePath(String value) >.K%W*t
{ ?vAhDD5
sFilePath = value; V!^0E.?a
} i}v.x
ZOa|lB (,
J!5b~8`v
public String getSFileName() zSfUM.fM
{ 9609
return sFileName; 6G"UXNa,
} GQ@mQ=i
,&M#[>\(3
.43cI(
public void setSFileName(String value) M")/6PH8
{ ;l @lA)i
sFileName = value; ivq(eKy
} 6z6\xkr
pXN'vP
?H@<8Ra=3
public int getNSplitter() s9nPxC&A
{ 2Zuo).2a.
return nSplitter; '#LzQ6Pn
} Lkx~>U
)&>W/56/
YMK ![ q-
public void setNSplitter(int nCount) K@cWg C
{ ~KkC089D
nSplitter = nCount; #m?)XB^_
} 5toa@#Bc%
} 5BXku=M
t;h`nH[
z5M6
/* -40X3
**Utility.java _~\} fY
*/ Is}kCf
package NetFox; &b5(Su
0^o/cSF
jED.0,+K!
public class Utility { ;e5PoLc
T~Bj],k_
u4SL:IH{D
public Utility() EUcD[Rv
{ BPt? 3tC
wDW%v@
*w*>\ZhOm
} -XCs?@8EQ
>Q=^X3to
//线程睡眠 Q#H"Se
public static void sleep(int nSecond) w0=
{ 23L>)Q
try{ jLVD37 P^
Thread.sleep(nSecond); =%IyR
} 6Nn+7z<*&z
catch(Exception e) 8t*sp-cy|
{ At=d//5FFP
e.printStackTrace (); H#;*kc a4
} GK'p$`oJm
} =tt3nfZ9
q: FhuOP
//日志 FV "pJ
public static void log(String sMsg) 4FRi=d;mP
{ ~,1Sw7rE
System.err.println(sMsg); R`a~8QVh&5
} ([<HFc`
$B%KkD
Ta?}n^V?;
public static void log(int sMsg) N2A6C$s
{ -W('^v_*
System.err.println(sMsg); ;;+AdN5
} Nv36#^Z
} iD_y@+iz
KU` *LB:
T&]-p:mg^
/* ~r8<|$;
**TestMethod.java qq&U)-`
*/ T*C25l;w
package NetFox; HBE[q#
-]zb3P
nD*iSb*
public class TestMethod { uWdF7|PN7
04|ZwX$>+
<.4(#Ebd
public TestMethod() Bgc]t
{ ///xx/weblogic60b2_win.exe eP>_CrJb
try{ >;c);|'}q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o$.#A]Flb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >{Hg+/
SiteFileFetch fileFetch = new SiteFileFetch(bean); %CiF;wJ
fileFetch.start(); C-c'"FHq
} P1LOj
catch(Exception e){e.printStackTrace ();} j%nN*ms
f- 9t
2n@`Og_0
} [//i "Nm
VrZfjpV
NLL"~
public static void main(String[] args) Ju47}t%HB
{ VM\R-[
new TestMethod(); "E2 0Y"[h
} Q+ V<&
} T@yQOD7
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