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)); 3<3t;&e
} ^(J-dK
for(int i=0;i<nEndPos.length-1;i++) ],AbcTX
{ 6# R;HbkO
nEndPos = nStartPos[i+1]; K)Ge
} oW8;^u
nEndPos[nEndPos.length-1] = nFileLength; g&P9UW>qS
} GV=V^Fl .
} eiOi3q
+yvBSpY
[XxA.S)x3
//启动子线程 ${e -ffyy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oR77`
for(int i=0;i<nStartPos.length;i++) vRxL&8`&
{ noFh p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -^0KE/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %$^$'6\77
nStartPos,nEndPos,i); gl Li
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :%pw`b, =V
fileSplitterFetch.start(); ga,A'Z
} aQC7V!v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3EO#EYAHiM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5t TLMZ`o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", []!tT-Gzy
nEndPos = " + nFileLength); N%:D8\qx
// fileSplitterFetch[nPos.length-1].start(); (]oFB$
N{|[R
!P+~c0DF
//等待子线程结束 #xDDh`
//int count = 0; UX03"gX
//是否结束while循环 *'s&/vEy
boolean breakWhile = false; Z5 w`-#
[sjrb?Xd
A7mMgb_
while(!bStop) 3J23q
{ _ak.G=
write_nPos(); /%c+ eL}l
Utility.sleep(500); <1v{[F_
breakWhile = true; 'Wd3`4V$
@fUX)zm>
vr5<LNCLQ
for(int i=0;i<nStartPos.length;i++) @DRfNJ}
{ 3XMBu*
if(!fileSplitterFetch.bDownOver) f'8B[&@L
{ i+kFL$N
breakWhile = false; "0p +SZ~D
break; HE8'N=0
} *)2x&~T*|
} "'Q$.sR
if(breakWhile) })h'""i&xn
break; `<. 7?
`\4RFr$
btJ,dpir
//count++; ;))[P_$zB
//if(count>4) 3uB=L7.
// siteStop(); Nn~tb2\vk
} My`josJ`Pb
zzDNWPzsA
{m1t~ S
System.err.println("文件下载结束！"); `Pz!SJ|
} "H/2r]?GT
catch(Exception e){e.printStackTrace ();} !07FsPI#{
} BVwRPt
4DG 9`5.
3(Hj7d7'}
//获得文件长度 "RR./e)h
public long getFileSize() LrmtPnL
{ Y,<WX v
int nFileLength = -1; $Sc08ro
try{ QBN=l\m+
URL url = new URL(siteInfoBean.getSSiteURL()); 3\+[38 _
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ynk><0g6
httpConnection.setRequestProperty("User-Agent","NetFox"); dd @COP?
m,kvEQ3
ZIGbwL
int responseCode=httpConnection.getResponseCode(); P5ESrZ@f
if(responseCode>=400) umHs"d
{ Y;%R/OyWY
processErrorCode(responseCode); Y`[HjS,
return -2; //-2 represent access is error ,&O:/|c E
} 80R=r
!pFKC)
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String sHeader; A+bubH,
t"!8
Xoa<r9
for(int i=1;;i++) s K$Sar
{ S3JygN*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rwV u?W
//Utility.log(in.readLine()); :BrnRW64
sHeader=httpConnection.getHeaderFieldKey(i); aF4V|?+
if(sHeader!=null) .-1{,o/&Q
{ >x_:=%Wr+
if(sHeader.equals("Content-Length")) #/ gme
{ *Tlws
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e4NX\tCpw
break; EssUyF-jwU
} }1^tK(Am
} 2Yg[8Tm#
else +XaO?F[c
break; "l2N_xX;
} lG^mW\O
} 3 v,ae7$U&
catch(IOException e){e.printStackTrace ();} e[VJ0 A=
catch(Exception e){e.printStackTrace ();} ]P ?#lO6
9Av- ;!]
N6 }i>";_;
Utility.log(nFileLength); `'k's]Y
yKk,);
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return nFileLength; f+W[]KK*PW
} /-<m(72wF
vEee/+1?
DuC u6j
//保存下载信息（文件指针位置） J;]@?(
private void write_nPos() 2*",{m
{ )bN3-_
try{ 0o'ML""j
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^}pREe c=
output.writeInt(nStartPos.length); I`}vdX)
for(int i=0;i<nStartPos.length;i++) / )u,Oa
{ X72X:"
// output.writeLong(nPos); kviSQM2
output.writeLong(fileSplitterFetch.nStartPos); fyoB]{$p8
output.writeLong(fileSplitterFetch.nEndPos); RlPByG5K
} lL+^n~g
output.close(); l$~bkVNL
} |"E9DD]{
catch(IOException e){e.printStackTrace ();} rls#gw
catch(Exception e){e.printStackTrace ();} >mDubP
} 5qB=@O]|G;
Ol5xyj
:H8L(BsI
//读取保存的下载信息（文件指针位置） ^E?V+3mV
private void read_nPos() U$JIF/MO_
{ Oqe.t;E 0}
try{ G(3la3\(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DczF0Ow
int nCount = input.readInt(); \osQwGPV
nStartPos = new long[nCount]; h9smviU7u
nEndPos = new long[nCount]; 4W-+k
for(int i=0;i<nStartPos.length;i++) .`#R%4Xl
{ *xVAm7_v
nStartPos = input.readLong(); 6zZR:ej
nEndPos = input.readLong(); +\$|L+@Z
} ;+KgujfU
input.close(); Ujzz`!mz
} *pUV-^uo
catch(IOException e){e.printStackTrace ();} &_hCs![
catch(Exception e){e.printStackTrace ();} u9~J1s<e
} G6bg ~V5Q:
tBUQf*B
xyWdzc](p
private void processErrorCode(int nErrorCode) ho$%7mc
{ [t)i\ }V
System.err.println("Error Code : " + nErrorCode); sBI%lrO
} ?t P/VL
RteTz_z{
wo9f99
//停止文件下载 =_6h{f&Q
public void siteStop() 7V``f:#d
{ / {~h?P}
bStop = true; {# _C
for(int i=0;i<nStartPos.length;i++) WN1-J(x6
fileSplitterFetch.splitterStop(); -RDs{c`y%N
Y &+/[[
X6 :~Rjim*
} =nZd"t'p|
} 8{t&8Ql n
//负责部分文件的抓取 =6YO!B>7
**FileSplitterFetch.java N)Kr4GC
*/ a[l5k
package NetFox; H;&t"Ql.
%n,bPa>T
@1Lc`;Wd
import java.io.*; ^uzVz1%mM
import java.net.*; ;mlIWn
[nD4\x+
}dl(9H=4
public class FileSplitterFetch extends Thread { j-|0&X1C
5Vqvb|
0VPa;{i/
String sURL; //File URL Ka{Zoi]
long nStartPos; //File Snippet Start Position *?&O8SSBH
long nEndPos; //File Snippet End Position czRh.kz,
int nThreadID; //Thread's ID (B#|3o
boolean bDownOver = false; //Downing is over ~T9[\nU\
boolean bStop = false; //Stop identical _"V0vV
FileAccessI fileAccessI = null; //File Access interface TD7ONa-,
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`<d>C}9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Pme?`YO$x
{ VRt*!v<")
this.sURL = sURL; rgY~8PY"
this.nStartPos = nStart; q4=RE
this.nEndPos = nEnd; M czWg
nThreadID = id; A[bxxQSP\H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OpQa!
} P0=F9`3wb
YSif`W!
y"ck;OQD
public void run() uX[ "w|
{ {9MYEN}FO
while(nStartPos < nEndPos && !bStop) Le!I-i(aD
{ T\>=o]
lOui{QU
}d(6N&;"zN
try{ _JH6bvbQ
URL url = new URL(sURL); E.9F~&DPJ<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sh1()vT
httpConnection.setRequestProperty("User-Agent","NetFox"); 7@?b_
String sProperty = "bytes="+nStartPos+"-"; -E7\.K3
httpConnection.setRequestProperty("RANGE",sProperty); |sh U
Utility.log(sProperty); uM8gfY)OI
"6i9f$N
vkK+ C~"
InputStream input = httpConnection.getInputStream(); _c2#
//logResponseHead(httpConnection); \2jY)UrQs
*)<tyIHd
zBbTj IFQ
byte[] b = new byte[1024]; FQyiIT6
int nRead; @j6D#./7j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BlUY9`VWh@
{ ]Gr'Bt/
nStartPos += fileAccessI.write(b,0,nRead); r!S iR(
//if(nThreadID == 1) *u}):8=&R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mI# BQE`p6
} Li2)~4p><
N+\*:$>zt6
( nh!tC
Utility.log("Thread " + nThreadID + " is over!"); ;IT^SHym
bDownOver = true; 3jNcL{
//nPos = fileAccessI.write (b,0,nRead); -AX3Rnv^!
} e([&Nr8h
catch(Exception e){e.printStackTrace ();} bA)Xjq)Rr
} luMNi^FQ
} C\{4<:<_&
1f=L8Dr
fAs:[
//打印回应的头信息 Cv|:.y
public void logResponseHead(HttpURLConnection con) vzw\f
{ A-W7!0
for(int i=1;;i++) 0e7!_/9
{ EVf'1^f
String header=con.getHeaderFieldKey(i); J.<m@\U
if(header!=null) n'ro5D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $?\],T
Utility.log(header+" : "+con.getHeaderField(header)); P}5aN_v\
else ,w6?} N
break; gDsZbmR
} #xc[)Y,W
} =4zsAa
!rWib`%
?o4&cCFOE
public void splitterStop() UW+I 8\^
{ <fw[7=_)^
bStop = true; <ygO?m{
} J=$v+8&.
te|VKYN%}[
bfJDF(=h
} x!< C0N>?z
lY1m%
1)r1/0
/* Pwq} ;+
**FileAccess.java GB+G1w
*//文件访问(定位，写) j.z#fU
package NetFox; Xm*Dh#H
import java.io.*; ;'h7 j*6
|!}$V
\z_@.Jw{
public class FileAccessI implements Serializable{ 65AOFH
PQfx0n,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0QGl'u{F
RandomAccessFile oSavedFile; }LM_VZj
long nPos; hE=cgO`QU
GL/\uq
+|}~6`
public FileAccessI() throws IOException ';1 c
{ 9Dpmp|
this("",0); cZwQ{9>
} RH`m=?~J,
U'\\(m|
8^^al!0K~
public FileAccessI(String sName,long nPos) throws IOException nK:39D$(
{ %(NRH?
oSavedFile = new RandomAccessFile(sName,"rw"); nBNZ@nD
this.nPos = nPos; {_ #
oSavedFile.seek(nPos); eZUK<&0x5
} iBZ+gsSP
_-D(N/
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public synchronized int write(byte[] b,int nStart,int nLen) LJBoS]~
{ i P/I% D
int n = -1; a#kZY7s
try{ `dj/Uk
oSavedFile.write(b,nStart,nLen); ^lQej%
n = nLen; _]<]:b
} onjTuZ^h
catch(IOException e) 's e9|:
{ -5Ccuk>6
e.printStackTrace (); 5B(|!Xq;I
} >8RIMW2
ln3.TR*
:?60pu=
return n; ok7DI
} (OJ}|*\e
z\;kjI
YN\ QwV
} QJ$]~)w?H
{xOu*8J
7}nOF{RH]
/* cW MZw|t
**SiteInfoBean.java oiklRf
*/ b?r0n]
package NetFox; (=p}b:Z
t[#`%$%'
F9d][ P@@
public class SiteInfoBean { ; I=z
!'+t)h9^
FL`. (,
private String sSiteURL; //Site's URL 0wOgQ n
private String sFilePath; //Saved File's Path Qi[T!1
private String sFileName; //Saved File's Name U:`rNHl
private int nSplitter; //Count of Splited Downloading File "+|>nA=7
d/7c#er
P~?u2,.E[
public SiteInfoBean() :pNZQX
{//nSplitter的缺省值为5 fF>H7
//default value of nSplitter is 5 _msDf2e9
this("","","",5); Va9vDb6
} #{N#yReh
4}8Xoywi1
:s8,i$Ex
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h7o{l7`)
{ OY?uqP}c
sSiteURL= sURL; mv+.5X
sFilePath = sPath; !&#CEF@J
sFileName = sName; 4,)=r3;&!
this.nSplitter = nSpiltter; sX@e1*YE_
D@\97t+
}De)_E\~
} \2~.r/`1
fV[xv4D.
&\1Dy}:
public String getSSiteURL() Rov0
{ x!G\-2#
return sSiteURL; uE/qraA
} b>fDb J0
4 9#I
!n !~Bw
public void setSSiteURL(String value) ,m0=zH4+:
{ =#1/<q)L
sSiteURL = value; -[+FVvS
} Av/|={i
5*ABw6'6
=. OWsFv
public String getSFilePath() E?%k
{ M"~B_t,Nw
return sFilePath; t-/%|@?D
} "zm.jNn
<$ '#@jW
]\Ez{MdAT
public void setSFilePath(String value) ]%NCKOM
{ qE(`@G
sFilePath = value; z#O{rwnl
} Qa"R?dfr
<;W4Th<4
rs\*$20
public String getSFileName() f61~%@fE
{ 40+E#z)
return sFileName; !74*APPHR
} a!wPBJJ
Be?mIwc_g
qOkw6jfluh
public void setSFileName(String value) a'Aru^el
{ 8CMI\yk
sFileName = value; P`RM"'Om
} <o p !dS
l$PO!JRD
|nMbf
public int getNSplitter() Br-bUoua
{ {T.$xiR
return nSplitter; [NC^v.[1[
} c9DX
At.WBa3j%{
,ad~6.Z_)
public void setNSplitter(int nCount) iSHNt0Nl
{ EYMwg_
nSplitter = nCount; )]rGGNF*
} Jd/5Kx
} )V~<8/)
FL0[V,
@4hxGk=
/* ^8E/I]-
**Utility.java awo=%vJ&
*/ mrk Q20D
package NetFox; 6lsU/`.
9?l( }S`
#_4L/LV
public class Utility { 2VMau.eQ
'U5 E{
@v@'8E Q
public Utility() &<k)W
{ S ^2'O7uj
Hq6VwQu?
Hm%[d;Z7
} C[<&%=
,_P(!7Z8
//线程睡眠 A~O 'l&KB
public static void sleep(int nSecond) $kkdB,y
{ Pbd#Fu;
try{ i8u9~F
Thread.sleep(nSecond); 2 R1S>X
} R0-ARq#0<
catch(Exception e) +1F@vag7
{ eAm7*2
e.printStackTrace (); Sg')w1
} oKzV!~{0M;
} st/Tb/
/8J2,8vZ
//日志 z[IG+2
public static void log(String sMsg) K#+TCZ,
{ 9CUMqaY2
System.err.println(sMsg); Y13IrCA2
} G@ed2T
YWd:Ok0
\1ys2BX
public static void log(int sMsg) KDg!Y(m{
{ oPm1`x
System.err.println(sMsg); ^ chlAQz(
} 9Ni$nZN
} DCP"
'00DUUa
LTBqXh
/* :,]%W $f=
**TestMethod.java BYNOgB1
*/ q\d'}:kfu
package NetFox; }5zH3MPQH
!i#;P9K
O_(J',++
public class TestMethod { /HI#8
Lr40rLx;u
;y4 "wBX
public TestMethod() VUagZ7p
{ ///xx/weblogic60b2_win.exe 'X@j
try{ mZMLDs:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9.SPxd~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )5'S=av9
SiteFileFetch fileFetch = new SiteFileFetch(bean); &eK8v]|"W
fileFetch.start(); ?6tuo:gP
} ,f}s!>j
catch(Exception e){e.printStackTrace ();} "1h|1'S50?
yZdM4`
/$+ifiFT
} 8~}Ti*Urc
7&l
19;\:tN
public static void main(String[] args) qo$<&'r
{ `Z/"Dd;F^3
new TestMethod(); vIz~B2%x
} HQv#\Xi1
} L!-T`R8'c
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