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)); -uv 9(r\P
} <}28=d
for(int i=0;i<nEndPos.length-1;i++) K-2o9No?j`
{ Gg=aK~q6
nEndPos = nStartPos[i+1]; KFTf~!|
} R<n8M"B
nEndPos[nEndPos.length-1] = nFileLength; L,C? gd@"
} aPD?Bh>JU
} $f<eq7rRe
}t@f|TX
m4Phn~>Gg
//启动子线程 3}>:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g[#k.CuP
for(int i=0;i<nStartPos.length;i++) 'DCKD4@C/
{ }zkL[qu;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c!\.[2n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jw/'*e
nStartPos,nEndPos,i); qs6Nb'JvQR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 935-{h@k
fileSplitterFetch.start(); MB]#%g&
} ~/j$TT"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gt =j5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XGE 2J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xb4Pt`x)rS
nEndPos = " + nFileLength); {E3xI2
// fileSplitterFetch[nPos.length-1].start(); Ne &Xf
o,?!"*EP
]regi- LGU
//等待子线程结束 DAjG*K{
//int count = 0; =oo[ Eyr
//是否结束while循环 $R A4U<
boolean breakWhile = false; h]kn%?fpmB
Z"6 2#VM
cr76cYq"Q
while(!bStop) t[]['Iosd
{ `Mg8]H~
write_nPos(); cJxW;WI!,
Utility.sleep(500); vC{h2A
breakWhile = true; \ V[;t-
t2=a(N-/,
Pv< QjY
for(int i=0;i<nStartPos.length;i++) M0cd-Dn
{ ~A^E
if(!fileSplitterFetch.bDownOver) G;2R]H#p
{ F;IP3tD
breakWhile = false; mSU@UD|'
break; C-Nuy1o
} J?._/RL8-
} qq OxTG]
if(breakWhile) fA"<MslKLK
break; \bU`
Qo'yS"g<9)
! G*&4V3Mg
//count++; f=t:[< )
//if(count>4) 7)B&(2D&
// siteStop(); x1t{SQ-C
} ctp?y
{/-y>sm
j_!bT!8
System.err.println("文件下载结束！"); }TSgAwsbC
} dX_!0E[c
catch(Exception e){e.printStackTrace ();} Wt>J`
} x|.v{tQa
fx<FIj7
sB?2*S"X)<
//获得文件长度 HwB {8S?sm
public long getFileSize() znt)]>f#
{ ?Fce!J
int nFileLength = -1; <v]z6B@9!
try{ ^:m^E0(H
URL url = new URL(siteInfoBean.getSSiteURL()); @'*eC}\E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [-4KY4R
httpConnection.setRequestProperty("User-Agent","NetFox"); K'x4l,rq
dw~[9oh
^uia`sOP4
int responseCode=httpConnection.getResponseCode(); *~cqr
if(responseCode>=400) 3I|O^
{ \,2gTi,=
processErrorCode(responseCode); w'A tf
return -2; //-2 represent access is error &B}Lo
} E_~x==cb
Yg/}ghF\
q7|:^#{av
String sHeader; #;`Oj
27m@|M] R
C`)_i3 ^
for(int i=1;;i++) b 8>q;
{ gc##V]OD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Hk@r5<{
//Utility.log(in.readLine()); XlVc\?
sHeader=httpConnection.getHeaderFieldKey(i); >W r$Y{
if(sHeader!=null) eI^gV'UK
{ {|z#70
if(sHeader.equals("Content-Length")) ?{eY\I
{ F$i$a b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R<|ejw
break; R\*)@[y9l
} s2^B(wP
} sm1;MF]/u
else ^00{Hd6
break; 'f*O#&?
} fuMN"T 6%+
} TtPr)F|
catch(IOException e){e.printStackTrace ();} #:#Dz.$L
catch(Exception e){e.printStackTrace ();} q]TqI' o
bw9 nB{C<
]BfS270
Utility.log(nFileLength); vs+QbI6>-
-j&Vtr
.Rvf/-e
return nFileLength; }S*/b1
} ZZ("-#?
#F!Kxks
^2EhlK^)
//保存下载信息（文件指针位置） }%$OU =T
private void write_nPos() ?KB@Zm+#~
{ Ad/($v5+
try{ xI?0N<'.*q
output = new DataOutputStream(new FileOutputStream(tmpFile)); eRs&iK2y
output.writeInt(nStartPos.length); ox[ .)v
for(int i=0;i<nStartPos.length;i++) (0OM"`j
{ 3V}(fnv
// output.writeLong(nPos); 96=Z"
output.writeLong(fileSplitterFetch.nStartPos); o&z!6"S<
output.writeLong(fileSplitterFetch.nEndPos); 3CM^j<9
} %G[/H.7s-
output.close(); F;P5D<
} -IU4#s
catch(IOException e){e.printStackTrace ();} s)ky/ce
catch(Exception e){e.printStackTrace ();} )t%h[0{{
} ?ok)>P
eLV.qLBUs
#dxvz^2V.3
//读取保存的下载信息（文件指针位置） /;l[I=VI
private void read_nPos() fagM7)x
{ #Ao !>qCE
try{ 1[-vD=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9Kbw GmSU
int nCount = input.readInt(); k][h9'
nStartPos = new long[nCount]; 2Lfah?Tx~C
nEndPos = new long[nCount]; E]1##6Ae
for(int i=0;i<nStartPos.length;i++) V&*D~Jq
{ NEVp8)w
nStartPos = input.readLong(); s?c JV`
nEndPos = input.readLong(); 5/?P|T
} @7W?8
input.close(); qSTWb%
} rslvsS:
catch(IOException e){e.printStackTrace ();} jXp. qK\"
catch(Exception e){e.printStackTrace ();} c<4F4k7
} ?Vc0)
VI_+v[Hk/
] 8Tzr
private void processErrorCode(int nErrorCode) 6+3$:?
{ jj,r <T
System.err.println("Error Code : " + nErrorCode); l5k?De_(x
} {<K=*rrZ
9x?'}
8sg|MWSU
//停止文件下载 Fp%Ln(/m
public void siteStop() Wp[9beI*M
{ ar$*a>'?
bStop = true; ?pG/m%[
for(int i=0;i<nStartPos.length;i++) =45W\
fileSplitterFetch.splitterStop(); kRlA4h1u_$
q]FBl}nwl%
9S>g6}[E#0
} +sf .PSz$
} !^WHZv4
//负责部分文件的抓取 S^N{wZo
**FileSplitterFetch.java :(,mL2[
*/ fu4!t31
package NetFox; 0V`[Zgf
dv!r.
,j178EX
import java.io.*; ?djQZ*
import java.net.*; opp!0:jS*
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C6jR=@42Q
public class FileSplitterFetch extends Thread { zN!j%T.e
BStk&b
kOjf #@c
String sURL; //File URL Lm6**v
long nStartPos; //File Snippet Start Position u =J&~
long nEndPos; //File Snippet End Position ~L{l+jK$p
int nThreadID; //Thread's ID VkZ.6kV
boolean bDownOver = false; //Downing is over =Op+v"
boolean bStop = false; //Stop identical (D7$$!}
FileAccessI fileAccessI = null; //File Access interface #;Tz[0
4W;S=#1
pe.QiMW{8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `A)"%~
{ h<x4YB5Mj
this.sURL = sURL; wCCV2tk
this.nStartPos = nStart; u0 y 1
this.nEndPos = nEnd; 2@khSWV
nThreadID = id; 4kl Ao$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X`JVR"=4
} ?*u*de[,
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gl7|H&&xV
public void run() }]6f+
{ f p[,C1U
while(nStartPos < nEndPos && !bStop) qCPmbg
{ %d;ezY'2
(sTuG}
t ls60h
try{ 1m@^E:w
URL url = new URL(sURL); 9 OT,TpA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N#ioJ^}n:
httpConnection.setRequestProperty("User-Agent","NetFox"); X+82[Y,mB.
String sProperty = "bytes="+nStartPos+"-"; :iUF7P1I
httpConnection.setRequestProperty("RANGE",sProperty); k'3Wt*i
Utility.log(sProperty); 6.c^u5;
Z?G&.# :
Vba.uKNjk
InputStream input = httpConnection.getInputStream(); (zcLx;N
//logResponseHead(httpConnection); M(Zc^P}N
I#rubAl
_$s> c!t,#
byte[] b = new byte[1024]; IV`%V+ f
int nRead; D(]E/k@;~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) & ,hr8
{ YY5!_k
nStartPos += fileAccessI.write(b,0,nRead); y~ rXl
//if(nThreadID == 1) `T&jPA9eY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z(13~38+
} wvby?MhPY
z rfUQO
O7G"sT1Dv
Utility.log("Thread " + nThreadID + " is over!"); kcuzB+
bDownOver = true; 7h9U{4r: M
//nPos = fileAccessI.write (b,0,nRead); 19UN*g3(
} y1f:?L-z
catch(Exception e){e.printStackTrace ();} 1;F`c`0<
} vVxD!EL
} s1j{x&OSq
g(E"4M@t!
t^tmz PWA
//打印回应的头信息 gm"#:< )
public void logResponseHead(HttpURLConnection con) }6u2*(TmD
{ 8|^CK|m6*
for(int i=1;;i++) {*m?Kc7k
{ SPkn3D6
String header=con.getHeaderFieldKey(i); ipE]}0q
if(header!=null) <wd]D@l7r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +9;2xya2
Utility.log(header+" : "+con.getHeaderField(header)); fS&6
else X[yNFW}S2W
break; h*i9m o
} C})'\1O%
} Zyf P;&
wq!iV |
q(M:QWA q
public void splitterStop() <%?#AVU[
{ r(A.<`\
bStop = true; \}0-^(9zd
} f58?5(Dc|
2{|$T2?e
{Qu"%h.Al
} 2}U!:bn(
KzUlTl0
muON>^MbC
/* <@v]H@E
**FileAccess.java f. }c7
*//文件访问(定位，写) C#0Qd%
package NetFox; Ah69 _>N`S
import java.io.*; xg@NQI@7
[{u(C!7L`
?#A]{l
public class FileAccessI implements Serializable{ 8hanzwoJ:
V~IIYB7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f9$xk|2g
RandomAccessFile oSavedFile; +j14Q$
long nPos; l! bv^
i]{1^pKq
3>M&D20Z
public FileAccessI() throws IOException !U%T&?E l
{ >w6taX
this("",0); @@G6p($
} -e GL)M
W!Gdf^Yy<
(.Y/
public FileAccessI(String sName,long nPos) throws IOException rh*sbZ68>E
{ 1Tp/MV/>
oSavedFile = new RandomAccessFile(sName,"rw"); $g9**b@
this.nPos = nPos; }n:?7
oSavedFile.seek(nPos); >R,'5:Rw
} U&Wwyu:4i
pmvT$;7I
^"\s eS
public synchronized int write(byte[] b,int nStart,int nLen) 8)*2@-Rp
{ Fh|#u:n
int n = -1; SymwAS+
try{ R7jmv n
oSavedFile.write(b,nStart,nLen); >r@.F%
n = nLen; K BE Ax3
} B;6]NCxD
catch(IOException e) 9LnN$e
{ ;h=*!7:
e.printStackTrace (); k*rZ*sSp
} `>(W"^
y;cUl, :v
zdl%iop3e
return n; = {'pUU
} 3\O|ii
.jw}JJ
{]*x*aa\
} rHge~nY<
J@pb[OL,
(:V>Hjt
/* +ECDD'^!
**SiteInfoBean.java _Q%vK*n
*/ ^g1f X1
package NetFox; S{]7C?4`
u9woEe?
Jq.lT(E8D
public class SiteInfoBean { O=cxNy-I
,fDEz9-,
`^JJ&)4iv
private String sSiteURL; //Site's URL n"PJ,ao
private String sFilePath; //Saved File's Path [D"t~QMr
private String sFileName; //Saved File's Name Y}*\[}l:&x
private int nSplitter; //Count of Splited Downloading File 'nQVj
'+>fFM,*B
N]EcEM#
public SiteInfoBean() 1LJuCI=~
{//nSplitter的缺省值为5 gJiK+&8I
//default value of nSplitter is 5 -$VZtex
this("","","",5); s&kQlQ=
} >>b3ZE|5
,C.:;Ime({
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public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AE`We$!
{ X[s8X!#
sSiteURL= sURL; =h6 sPJ
sFilePath = sPath; b !@Sn/
sFileName = sName; qW:)!z3\
this.nSplitter = nSpiltter; 'TC/vnM
.MW@;
`i) 2nNJ"
} `(+o=HsD
iB0WEj[?
,r^M?>
public String getSSiteURL() r"2V
{ 5AS[\CB4
return sSiteURL; Qp"y?S
} 4to% `)]
Xv <G-N4
a {}|Bf<
public void setSSiteURL(String value) G&xo1K]
{ hv6@Jr3
sSiteURL = value; _Y=2/*y^
} <^~FLjsfg
.?p\n7
jN-vY<?h]
public String getSFilePath() P7ph}mB
{ etT +
return sFilePath; H.<a`mm8
} e~ aqaY~}
JjpRHw8\
n%R;-?*v
public void setSFilePath(String value) FlfI9mm
{ zl-2$}<a
sFilePath = value; V@7KsB
} K3uG2g(>2
oRKEJNps
kg][qn|>J]
public String getSFileName() jV#ahNq;
{ n?\ nn3
return sFileName; `nKH"TaX
} &R|/t:DN
fP tm0.r
(>6*#9#p
public void setSFileName(String value) +x9cT G
{ {e|*01hE
sFileName = value; |py6pek|
} uPYmHA}_/
gj\)CBOv
q#Zs\PD
public int getNSplitter() ZvYLL{>}w
{ QB:i/9
return nSplitter; 4k/VBZB
} E3@QI?n^^
=.]l*6WV
[S.ZJUns
public void setNSplitter(int nCount) RT93Mt%P
{ < v]3g
nSplitter = nCount; <R%;~){
} 6Ao%>;e*
} BQcE9~H
JGC=(;
kyAXRwzI
/* O3N0YGhJ
**Utility.java I$Qs;- (
*/ 5qg2Zc~
package NetFox; 4`Q3v4fOF
;fw1
ky 8ep
public class Utility { ml@2wGyf
tNsPB6Z
"fg](Cp[z
public Utility() cJM:
{ <APB11
mrm^e9*Z
=X?\MVWB
} ) \Y7&
i>EgG5iJ
//线程睡眠 7NC=*A~
public static void sleep(int nSecond) 1h*)@
{ 9ukg}_Hx
try{ D+~_TA
Thread.sleep(nSecond); 1)}=bhT
} k5kdCC0FCk
catch(Exception e) h8\ T
{ th6+2&B6
e.printStackTrace (); Qn ^bVhG+
} o7B[R) 4
} 5L:1A2Z?c
|AlR^N
//日志 yNm:[bOER
public static void log(String sMsg) Z5c~^jL$-
{ /h v4x9
System.err.println(sMsg); k3+e;[My+
} >7!6nF3x,
tb:L\A^:
%Pksv}
public static void log(int sMsg) l5+gsEux]
{ |F.)zC5{
System.err.println(sMsg); ,!V]jP)
} @&D?e:|!U
} ;> m"x
[2ax>Yk$
vP7K9Kx
/* GDYFU*0
**TestMethod.java 9%*wb`&
*/ >3awn*N
package NetFox; :'aAZegQY
3E f1bhi
/-6S{hl9Ne
public class TestMethod { 8/z3=O&
SuZ&vqS
Z):n c% S
public TestMethod() R3k1RE2c&g
{ ///xx/weblogic60b2_win.exe Ro2d,'
try{ OD Ur
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7iJ&6=/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j@Yi`a(sdm
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0 ugT2%
fileFetch.start(); FWH}j0Gj|
} j3q~E[Mz\
catch(Exception e){e.printStackTrace ();} E7Cy(LO
+UJuB
_C\[DR0n
} =)O,`.M.Y
47r_y\U h
g%u&Zkevx
public static void main(String[] args) 56l@a{
{ "P)*FT
new TestMethod(); 8q`$y$06Dk
} ^-FRTC
} |[9?ma
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