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)); ~gX@2!D5k
} jMw;`yh
for(int i=0;i<nEndPos.length-1;i++) 3$y]#L
{ 6QxLHQA
nEndPos = nStartPos[i+1]; moc_}(
} NtA}I)'SWU
nEndPos[nEndPos.length-1] = nFileLength; <'gCIIa2
} sL!6-[N
} xE0+3@_>>
z?yADYr9
8:0l5cZE
//启动子线程 /}M@MbGMM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >i=O =w
for(int i=0;i<nStartPos.length;i++) %K%8 ~B
{ [[bMYD1eO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @AyC0}
nStartPos,nEndPos,i); 1"!<e$&$X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F<^,j7@
fileSplitterFetch.start(); ^Yn6kF
} x^C,xP[#Y;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^ qE4:|e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 31bKgU{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "@Te!.~A.
nEndPos = " + nFileLength); 6aj)Fe'2
// fileSplitterFetch[nPos.length-1].start(); NIYAcLa@n8
rW1>t+
\!631FcQ
//等待子线程结束 3g5i5 G\
//int count = 0; \l]jX: 9(
//是否结束while循环 2 3>lE}^G
boolean breakWhile = false; Z4t9q`}h
^ S%4R'
UQTt;RS*zS
while(!bStop) bJe^x;J9
{ 9@:&E
write_nPos(); k:d'aP3
Utility.sleep(500); i5)trSM|
breakWhile = true; qkR.{?x
+\}]`uS:
3S.rIai+
for(int i=0;i<nStartPos.length;i++) }~A-ELe:
{ y`\/eX
if(!fileSplitterFetch.bDownOver) .oSKSld
{ {N _v4})
breakWhile = false; ,ciNoP*-~%
break; hL8QA!
} q Rtgk
} w|RG
if(breakWhile) 4>, <b1Y
break; N"2@yaN
ZPMX19
(zTr/
//count++; u}u2{pO!
//if(count>4) u2!8'-Ai
// siteStop(); 2{&|%1Jg
} ,@[Q:fY
E=7"};
pX!S*(Q{
System.err.println("文件下载结束！"); <'s1+^LC
} q4U?}=PD
catch(Exception e){e.printStackTrace ();} X|8Yz3:o
} Kj'm<]u
Rfgc^3:j
Gz6FwU8L
//获得文件长度 B4J^ rzK
public long getFileSize() VS 8|lgQ
{ Y6g[y\*t
int nFileLength = -1; 3xj<ATSe
try{ 9K)OQDv%6D
URL url = new URL(siteInfoBean.getSSiteURL()); |e+I5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wV U(Du
httpConnection.setRequestProperty("User-Agent","NetFox"); q>H!?zi\Hy
fHwh6|
;9;.!4g/T
int responseCode=httpConnection.getResponseCode(); tuUk48!2I
if(responseCode>=400) W_M]fjL.
{ 4jar5Mz
processErrorCode(responseCode); Z0E+EMo
return -2; //-2 represent access is error czedn_}%Q
} ~A"ODLgU9
tCA |sN
)V9$ P)
String sHeader; 5*4P_q(AxD
a0AIq44
0w(<pNA
for(int i=1;;i++) ~LkReQI
{ bt~-=\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5"@<7/2qI
//Utility.log(in.readLine()); ^t#]E#
sHeader=httpConnection.getHeaderFieldKey(i); _}Z*%sT
if(sHeader!=null) PhW#=S
{ xb1)ZJH
if(sHeader.equals("Content-Length")) 8xL-j2w
{ mp@JsCU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LfF<wDvXf
break; Lmj?V1% V
} dJCu`34Y'|
} uOZ+9x(
else lr^-
break; +mAMCM2N
} T@k&YJ
} ?#]c{Tlpz
catch(IOException e){e.printStackTrace ();} >5]Xl*{H)
catch(Exception e){e.printStackTrace ();} vA+RZ
m>UJ; F
!Ng^k>*h
Utility.log(nFileLength); f~"3#MaV
ZXr]V'Q?
+5^*c^C
return nFileLength; J$'T2@H#
} AKL~F|t
7tfFRUw
pk"JcUzR
//保存下载信息（文件指针位置） 0Z9jlwcQ
private void write_nPos() rytizbc
{ (<1DPpy95O
try{ {|>~#a49h
output = new DataOutputStream(new FileOutputStream(tmpFile)); !%5{jO1
output.writeInt(nStartPos.length); 1w\Y._jK
for(int i=0;i<nStartPos.length;i++) /\Q{i#v
{ QmgwIz_
// output.writeLong(nPos); 2X6y^f';\
output.writeLong(fileSplitterFetch.nStartPos); d6(qc< /!r
output.writeLong(fileSplitterFetch.nEndPos); >%d]"]
} ?J)%.~!
output.close(); 9lny[{9
} xcoYo
catch(IOException e){e.printStackTrace ();} y)/d-
catch(Exception e){e.printStackTrace ();} u4Vc:n
} 0aGfz=V&
vy-{BH
a9D5qj
//读取保存的下载信息（文件指针位置） ?u8+F
private void read_nPos() .,EZ-&6{
{ J-u,6c
try{ t,MK#Ko
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +R*4`F:QJQ
int nCount = input.readInt(); j*+r`CX
nStartPos = new long[nCount]; r$0=b -
nEndPos = new long[nCount]; ?k"KZxpT
for(int i=0;i<nStartPos.length;i++) Up/1c:<J
{ *TMg.
nStartPos = input.readLong(); {\0R[+d
nEndPos = input.readLong(); /:%^Vh3XF
} 4"7Qz z
input.close(); GW}KmTa]&
} Yh"Z@D[d
catch(IOException e){e.printStackTrace ();} /G84T,H
catch(Exception e){e.printStackTrace ();} So!1l7b
} hvpn=0@M
%/'[GC'y!
XY%8yII6
private void processErrorCode(int nErrorCode) 85s{;3
{ 0A}'.LI
System.err.println("Error Code : " + nErrorCode); oWJ}]ip
} ifBJ$x(B.
gg8T],s1!a
dQ^k-
//停止文件下载 8vUP{f6{
public void siteStop() JgK?j&!hs:
{ s]B^Sz=
bStop = true; {5_*f)$[H
for(int i=0;i<nStartPos.length;i++) -j<UhW
fileSplitterFetch.splitterStop(); Z{ p;J^:
\,(tP:o
kXG+zsT
} a(}jn|
} 8q0f#/`v
//负责部分文件的抓取 kfmIhHlYQ
**FileSplitterFetch.java ^5GS!u"
*/ ,lN!XP{M6w
package NetFox; O|gb{
DR=>la}!
/CZOO)n
import java.io.*; Pu*st=KGB
import java.net.*; h[B Ft{x
J(l6(+8
@MN>ye'T
public class FileSplitterFetch extends Thread { 06=eA0JI
WG^D$L:
)3u[btm
String sURL; //File URL zV2c`he%z
long nStartPos; //File Snippet Start Position "4r5n8
long nEndPos; //File Snippet End Position 3a#!^G!~
int nThreadID; //Thread's ID Rl S=^}>
boolean bDownOver = false; //Downing is over iP_rEi*-J
boolean bStop = false; //Stop identical i.fDH57
FileAccessI fileAccessI = null; //File Access interface se)I2T{J
4&&j7$aV
EIF[e|kZ<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oxad}Y
{ m:"2I&0)WM
this.sURL = sURL; JG4&eK$-
this.nStartPos = nStart; $~`(!pa:
this.nEndPos = nEnd; Mz"kaO
nThreadID = id; esLY1c%"/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m\~[^H~g
} #b8/gRfS
:z"Uw*
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public void run() 3^`bf=R
{ w=f8UtY9@A
while(nStartPos < nEndPos && !bStop) ^Xb!dnT.*a
{ bUWtlg
p=r{ODw#3
I#A`fJ
try{ j+Tk|GRab
URL url = new URL(sURL); C8{CKrVE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e`_3= kI
httpConnection.setRequestProperty("User-Agent","NetFox"); V];RQWs
String sProperty = "bytes="+nStartPos+"-"; L9AfLw5&X
httpConnection.setRequestProperty("RANGE",sProperty); K}$PIW
Utility.log(sProperty); ev+NKUi=
S[ 2`7'XV
Ads^y`b
InputStream input = httpConnection.getInputStream(); Bq2}nDP
//logResponseHead(httpConnection); LLU>c]a
d3 N %V.w
5aWKyXBIx
byte[] b = new byte[1024]; z&-`<uV~
int nRead; h?CNChRJs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t8^*s<O
{ 0\gE^=o[
nStartPos += fileAccessI.write(b,0,nRead); w$t2Hd
//if(nThreadID == 1) f,?7,?x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '7=*n_l
} RhDa`kV%t
(8>k_
^\wosB3E
Utility.log("Thread " + nThreadID + " is over!"); eM~i (]PY
bDownOver = true; /Pf7=P
//nPos = fileAccessI.write (b,0,nRead); :!#-k
} ,f1+jC
catch(Exception e){e.printStackTrace ();} dk3\~m%Pv
} dkVVvK
} L~;_R*Th
v'iQLUgI
T&0tW"r?
//打印回应的头信息 =|G PSRQ
public void logResponseHead(HttpURLConnection con) 5N[Y2
{ M.l;!U!}
for(int i=1;;i++) Ao]F_hZ
{ 0umfC
String header=con.getHeaderFieldKey(i); "5YsBih
if(header!=null) )<~b*^kl\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +)F8YMg e
Utility.log(header+" : "+con.getHeaderField(header)); w}2yi#E[
else dvxH:,
break; /evh.S
} 6: M
} ;aFQP:l/
RnTPU`
O=+C Kx@
public void splitterStop() ksK lw_%o
{ "%Rx;xw|
bStop = true; P|6m%y
} i\PN
j5RMS V
#G\)ZheG
} u{_T,k<!
Y- w5S|!
2Nj0 Hqjq
/* `bxgg'V
**FileAccess.java r<0.!j%c
*//文件访问(定位，写) :`uo]B"
package NetFox; c[;I\g
import java.io.*; VX- f~
0_Y;r{3m"
z24-hC
public class FileAccessI implements Serializable{ LAvAjvRc
yC _X@o-n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Fs=nAn#
RandomAccessFile oSavedFile; IYj-cm
long nPos; 1Ju{IEV
I)sCWC:Mq~
L'Wcb =;
public FileAccessI() throws IOException wv*r}{%7g[
{ F4:ssy^
this("",0); dFS+O;zE\
} Uh7kB`2
*D9QwQ _|
3W27R
public FileAccessI(String sName,long nPos) throws IOException sDwSEg>#B
{ t;? q#!uc
oSavedFile = new RandomAccessFile(sName,"rw"); 3XA^{&}
this.nPos = nPos; TQ>1u
oSavedFile.seek(nPos); pQqZ4L6v
} '8W}|aF
LS \4y&J40
_Fer-nQ2R
public synchronized int write(byte[] b,int nStart,int nLen) au#IA
{ M9iu#6P
int n = -1; Ml)WY#7
try{ q_I''L
oSavedFile.write(b,nStart,nLen); "%sW/ph
n = nLen; 3_D$6/i
} 0/*z]2
catch(IOException e) y6Rg@L&U
{ muY4:F.C(
e.printStackTrace (); mH8"k+k
} =?/J.[)<*
\?}ZXKuJj
ABx0IdOcI
return n; {Ji[d.cY
} fdPg{3x*k
iveWau292
Ddu$49{S:
} T}zOM%]]
"V^(i%E;
]pFYAe ?
/* e0aeiG$/0
**SiteInfoBean.java L>xN7N3&m
*/ T}g;kppC
package NetFox; _jr%s
BG=h1ybz
ni3^J5XW
public class SiteInfoBean { V-)q&cbW]q
iHR?]]RF
WSh+5](:
private String sSiteURL; //Site's URL qf'uXH
private String sFilePath; //Saved File's Path ?6a:!^eL
private String sFileName; //Saved File's Name 6@nEcr
private int nSplitter; //Count of Splited Downloading File 2avSsN{^
;BpuNB
;Cv x48
public SiteInfoBean() G<>`O;i
{//nSplitter的缺省值为5 #LcF;1o%o2
//default value of nSplitter is 5 rH & ^SNc
this("","","",5); I*'QD)
} S=o Ab&
j'v2m6/
xeZ,}YP)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A]W`r}
{ 3VcG /rf
sSiteURL= sURL; I]zCsT.
sFilePath = sPath; )|*HkdF`
sFileName = sName; QQ pe.oF
this.nSplitter = nSpiltter; ;K`qSX;;c(
TqzkF7;k4
yfi.<G)S
} rq+E"Uj?
)x8Izn
P1)9OE
public String getSSiteURL() 5{j1<4zxR
{ [1l,I[
return sSiteURL; 8/]5h%
} pOx0f;'G+
,US]
0f1*#8-6
public void setSSiteURL(String value) XlR.Y~
{ 1?Wk qQ
sSiteURL = value; ~%>ke
} Q]66v$
3>c<E1
+Z/Pj_.o
public String getSFilePath() Pij*?qmeQ
{ qm]k (/w
return sFilePath; U^:+J-z{
} CH!Lf,G
YY'46
qMKXS,s
public void setSFilePath(String value) Bv@NE2
{ 1Hk`i%
sFilePath = value; uq{w1O5
} 11O^)_|c
1iig0l6\m
#r>
public String getSFileName() xyBWV]Y
{ R$_#7>3
return sFileName; [|E 93g
} z-ra]
SW# 5px`
4h|sbB"t
public void setSFileName(String value) w%KU@$
{ wtIXZUx
sFileName = value; M qFuZg
} w+z~Mz}Vz
Xu2:yf4No*
"NMX>a,(
public int getNSplitter() Hq ]f$Q6:
{ Fe{lM' 8
return nSplitter; dXg.[|S*
} Wz;7 |UC
-Uh3A\#(
s<h]2W
public void setNSplitter(int nCount) :I[nA?d[&
{ STtjkZ6
nSplitter = nCount; :bNqK0[rS
} $!H;,Jxv
} 7vF+Di(B
Rm>AU=
ViKN|W>T
/* M&wf4)*%0+
**Utility.java *QH@c3vUe\
*/ 8{^zXJi]m
package NetFox; O3x9S,1i
Pp#
3"!h+dXw
public class Utility { o'+p,_y9Y@
p48mk
DI"KH)XD
public Utility() ckykRqk}
{ /m"O.17N
=ss(~[
8eGq.+5G
} 62)Qr
J2W#vFe\
//线程睡眠 FN0)DN2d}
public static void sleep(int nSecond) waT'|9{
{ Kg4\:A7Sa.
try{ bys5IOP{]o
Thread.sleep(nSecond); KW`^uoY$
} 9EHhVi
catch(Exception e) g3B%}!|
{ zZR_&z<
e.printStackTrace (); b\^X1eo
} =hL;Q@inb
} |Y"nZK,
J[ ;g \
//日志 5e1;m6
public static void log(String sMsg) f=:ycd!
{ (qo ?e2K
System.err.println(sMsg); x *:v]6y
} !p #m?|Km
g6aIS^mU
wo>7^ZA
public static void log(int sMsg) ,58XLu
{ `X)y5*##wq
System.err.println(sMsg); gV~_m
} 5NGQWg
} N_L~oX_
[L(qrAQ2|z
V?t56n Y}
/* i=3~ h Zl
**TestMethod.java c6-~PKJL
*/ 9 n0?0mk
package NetFox; ?$$Xg3w_#
-,:^dxE'
}ZqnsLu[)
public class TestMethod { )?y${T
}jdMo83
Y[sBVz'j5
public TestMethod() +-2W{lX
{ ///xx/weblogic60b2_win.exe -<0xS.^
try{ 88uoA6Y8h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 10}<n_I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -8zdkm8k
SiteFileFetch fileFetch = new SiteFileFetch(bean); tEuVn5
fileFetch.start(); :Eb=jWA
} Y' FB {
catch(Exception e){e.printStackTrace ();} 80_}}op?8
d#(ffPlq
1L;3e@G
} MxLg8,M
nQ+$
v]h^0WU
public static void main(String[] args) +khVi}
{ CXiDe)|<E
new TestMethod(); V*6o|#
} {Qba`lOkq
} z&wJ"[nOC
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