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)); b?'yAXk
} -xP!"
for(int i=0;i<nEndPos.length-1;i++) 4f;HQ-Iv
{ RZCq{|L
nEndPos = nStartPos[i+1]; Q6r7.pk"SU
} pn^ d]rou?
nEndPos[nEndPos.length-1] = nFileLength; G2FXrkU
} ]H1I,`=@
} LA)[ip4
tq|hPd<C
@i*|s~15
//启动子线程 7!N2-6GV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lMbAs.!
for(int i=0;i<nStartPos.length;i++) %Ijj=wW
{ \0gM o&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #KiRfx4G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }3L@J8:D"
nStartPos,nEndPos,i); A\.GV1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^) s2$A:L
fileSplitterFetch.start(); L{`JRu
} E)fglYWs2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {qa Aq%'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @#-q^}3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <(-hx+^
nEndPos = " + nFileLength); /n8B,-Z5s5
// fileSplitterFetch[nPos.length-1].start(); w/K_B:s
HC}YY2
:]1TGfS
//等待子线程结束 ziCHjqT
//int count = 0; ,YMp<C
//是否结束while循环 aT$9;
boolean breakWhile = false; _zwUE
'uxX5k/D@t
) v,:N.@Q
while(!bStop) Ck|8qUz-
{ L;f!.FX#
write_nPos(); 5kz)5,KjM
Utility.sleep(500); ,c)uX#1
breakWhile = true; 2]ape !(
>cCR2j,r
VH1d$
for(int i=0;i<nStartPos.length;i++) =>! Y{: y(
{ ]]wA[c~G
if(!fileSplitterFetch.bDownOver) }B.H|*uO
{ 7?%k7f
breakWhile = false; v*[.a#1^
break; oGRhnP'PF+
} M )2`+/4
} G-.^O,%
if(breakWhile) #"5 Dk#@
break; aqc?pqM
$+I;oHWI
^~A>8CQOU
//count++; n;T7=1_"
//if(count>4) UZpIcj cL
// siteStop(); <N9[?g)
} %&Q$dzgb_
aWY gR
_&b4aW9<
System.err.println("文件下载结束！"); 4sT88lG4n
} Z7?~S2{c
catch(Exception e){e.printStackTrace ();} '`uwJ&@
} wL:flH@
:65~[$2
W0]gLw9*
//获得文件长度 5qP:/*+
public long getFileSize() ZXuv CI
{ %GS(:]{n
int nFileLength = -1; XUlS\CH@{
try{ Uh):b%bS;J
URL url = new URL(siteInfoBean.getSSiteURL()); fk x \=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a,WICv0E
httpConnection.setRequestProperty("User-Agent","NetFox"); L');!/:
KW^7H
y;o^- O
int responseCode=httpConnection.getResponseCode(); BjzPz
if(responseCode>=400) .ODR]7{
{ q*7VqB
processErrorCode(responseCode); vsl]92xI
return -2; //-2 represent access is error x" L20}
} :FTMmW,>'
eF3,2DDC
{>)#HD
String sHeader; _<OSqE
vG"=h%
uD@#
for(int i=1;;i++) z\%Ls
{ `.Qi?* ^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9uA>N
//Utility.log(in.readLine()); VQS~\:1
sHeader=httpConnection.getHeaderFieldKey(i); ~15N7=wCM
if(sHeader!=null) z3;*Em8Ir
{ #a8B/-
if(sHeader.equals("Content-Length")) VN\W]jT
{ @-!}BUs?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); suzZdkMA
break; DuHu\>f<S
} %YC_Se7
} 1BpiV-]=
else [CXrSST")E
break; ?3.b{Cq{-
} /VN f{p
} ]33>m|?@
catch(IOException e){e.printStackTrace ();} ^>hWy D
catch(Exception e){e.printStackTrace ();} lUvpszH=
)j0TeE1R
TO?R({yx*
Utility.log(nFileLength); 7OJ'){R$
Gf<'WQ[
ikvWh<=>H
return nFileLength; r 0iK
} l)&X$3?tz
esMX-.8Cx
ap+JQ@b
//保存下载信息（文件指针位置） s pp f
private void write_nPos() ~2QR{; XQ
{ }%_ b$
try{ \}"$ ?d'f
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~U@;gLoD
output.writeInt(nStartPos.length); n4R(.N00
for(int i=0;i<nStartPos.length;i++) io-![^{
{ LH8 fBhw
// output.writeLong(nPos); J2xw) +
output.writeLong(fileSplitterFetch.nStartPos); ~ijVmWNk
output.writeLong(fileSplitterFetch.nEndPos); B=^)Ub5'
} ov_j4j>6P
output.close(); [8=vv7wS
} ?-dX`n
catch(IOException e){e.printStackTrace ();} 6&!PmKFO.
catch(Exception e){e.printStackTrace ();} <?riU\-]y
} ='s(|
F.=2u"[*&
G?;e-OhV
//读取保存的下载信息（文件指针位置） f-`)^5E
private void read_nPos() yEhTNBa*h{
{ :<bB?N(
try{ #0P$M!%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4O)1uF;
int nCount = input.readInt(); v{ 0=
nStartPos = new long[nCount]; 0dGAP
nEndPos = new long[nCount]; e'~J,(fB
for(int i=0;i<nStartPos.length;i++) P'Ux%Q+B>
{ UJCYs`y
nStartPos = input.readLong(); (2^gVz=j
nEndPos = input.readLong(); 2[O&NdP\Zk
} ~l]ve,W[
input.close(); {pnS Q
} ,P70Jb
catch(IOException e){e.printStackTrace ();} jw^<IMAG\8
catch(Exception e){e.printStackTrace ();} hp5|@
} 2Q/4bJpd
mUdOX7$c>
QSszn`e
private void processErrorCode(int nErrorCode) pgQV/6
{ 4GY[7^
System.err.println("Error Code : " + nErrorCode); ]pNvxXbeW
} 1+jAz`nA:T
]<cK";
w1OI4C)~
//停止文件下载 O$&mFL[`
public void siteStop() ,}ECF>
{ CsoiyY -2
bStop = true; i*Sqda $
for(int i=0;i<nStartPos.length;i++) FtfKe"qw
fileSplitterFetch.splitterStop(); -xEXN[\S
%t" CX5n
UQC=g
} Vr^n1sgE}r
} kT"Kyd
//负责部分文件的抓取 +'I+o5*
**FileSplitterFetch.java B&[M7i
*/ W;'!gpa
package NetFox; VcSVu
2\jPv`Ia
LWz&YF#T-
import java.io.*; YkniiB[/
import java.net.*; w35J.zn
]+XYEv
Z{ X|6.
public class FileSplitterFetch extends Thread { ?fUlgQ}N
r^3acXl
-EkWs/'h
String sURL; //File URL G MX?
long nStartPos; //File Snippet Start Position $c:ynjL|P-
long nEndPos; //File Snippet End Position Vzdh8)Mu\
int nThreadID; //Thread's ID W&&;:Fr
boolean bDownOver = false; //Downing is over vd 0ljA
boolean bStop = false; //Stop identical HkUWehVm
FileAccessI fileAccessI = null; //File Access interface pgI^4h
q_g+Jf P-D
)4gJd? 8R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6@{(;~r
{ VEqS;~[
this.sURL = sURL; }L+L"l&
this.nStartPos = nStart; %,6#2X nX%
this.nEndPos = nEnd; Sa?ksD2IaB
nThreadID = id; TDFkxB>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #LL?IRH9^
} zF8dKFE~
:Q $K<)[
q Gw -tPD<
public void run() gX]-\
{ njScz"L~
while(nStartPos < nEndPos && !bStop) +eyc`J
{ s:/8[(A
4'`{H@]tb
\N!AXD
try{ U(Nu%
URL url = new URL(sURL); % NA9{<I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fPn>v)lN{
httpConnection.setRequestProperty("User-Agent","NetFox"); 5NS[dQG5
String sProperty = "bytes="+nStartPos+"-"; %r%Mlj:#
httpConnection.setRequestProperty("RANGE",sProperty); KxYwJ
Utility.log(sProperty); Rs-]N1V
86 W9rR
F)&@P-9+
InputStream input = httpConnection.getInputStream(); aY'C%^h]
//logResponseHead(httpConnection); x(etb<!jd
#{?PbBE}
P9^-6;'Y
byte[] b = new byte[1024]; >/kcdWl
int nRead; uxtWybv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q[vJqkgT
{ wRcAX%n&
nStartPos += fileAccessI.write(b,0,nRead); Kwefs;<E?
//if(nThreadID == 1) \Xm,OE_v"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &]e'KdXF
} s2'yY(u/
TUV&vz{
,SynnE68
Utility.log("Thread " + nThreadID + " is over!"); Szq/hv=Q
bDownOver = true; < Z{HX[y
//nPos = fileAccessI.write (b,0,nRead); L;VoJf
} Cjqklb/
catch(Exception e){e.printStackTrace ();} iop2L51eJ
} C([phT;
} Vr6@>@SC
S1p;nK
*.sVr7=j
//打印回应的头信息 v0-cd
public void logResponseHead(HttpURLConnection con) 42e|LUZg
{ SM0~fAtE
for(int i=1;;i++) tZ=E')!\
{ C${Vg{g7a
String header=con.getHeaderFieldKey(i); {QcLu"?c
if(header!=null) gVq;m>\|F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4L ;% h
Utility.log(header+" : "+con.getHeaderField(header)); WHsgjvh"
else tBq nfv
break; pm*xb]8y
} k9:{9wW
} y.e^hRKb
o<<xY<
1rv)&tKs
public void splitterStop() ])|d"[ur=
{ %_+2@\
bStop = true; M9V q -U18
} rR9|6l 3
mef<=5t
[5zx17'
} Izhee%c
,sA[)wP{
G;v8$)Zj
/* #33fGmd[
**FileAccess.java r"``QmM
*//文件访问(定位，写) %X4xv_o`f
package NetFox; WF1px%
import java.io.*; 8P^ITL z%
c(:f\Wc3Z
U*(izD
public class FileAccessI implements Serializable{ &u /Nf&A
[s"O mAy4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4{hps.$?~
RandomAccessFile oSavedFile; X%Z{K-
long nPos; @y='^DQ*
9:ze{ c $
LQtj~c>X-|
public FileAccessI() throws IOException |zQ4u
{ P;P%n
this("",0); g .onTFwN
} lJu;O/
J?RabYd ~
eoai(&o0$
public FileAccessI(String sName,long nPos) throws IOException W=#:.Xj[
{ !n* +(lZ
oSavedFile = new RandomAccessFile(sName,"rw"); 9Wnn'T@Tl
this.nPos = nPos; +?u~APjNN
oSavedFile.seek(nPos); q#vQv5
} ]bj&bk#
.q `Hjmg<
Xe<sJ.&Wf
public synchronized int write(byte[] b,int nStart,int nLen) ]$Yvj!K*Q
{ Fs{x(_LOr
int n = -1; q;<h[b?
try{ ~aMlr6;
oSavedFile.write(b,nStart,nLen); ^cczJOxB
n = nLen; \^ZlG.
} P%{^i]
catch(IOException e) 1QLbf*zeIW
{ |+iws8xK?
e.printStackTrace (); txiP!+3OWB
} 5&v~i\Q
LXbP 2
^Wc@oa`
return n; 0Uo\wyd
} FrTi+& <
AWP"b?^G|
]|MEx{BG-
} .Xce9C0SW
( M7pT
1#.>a$>
/* Z @^9PQG$
**SiteInfoBean.java J3n-`k8
*/ Tav*+
package NetFox; ?YZ- P{rTS
``ou/Z
JBJhG<J
public class SiteInfoBean { _59huC.
g=QDu7Ux
c|M6<}
private String sSiteURL; //Site's URL -amBB7g
private String sFilePath; //Saved File's Path Zrvz;p@~
private String sFileName; //Saved File's Name a#>Yh;FA
private int nSplitter; //Count of Splited Downloading File MC<PM6w
_(h&7P9
T(t+ iv
public SiteInfoBean() A<1hOSCz\
{//nSplitter的缺省值为5 n}'=yItVL1
//default value of nSplitter is 5 c17_2 @N
this("","","",5); _tBTE%sO
} S<4c r
/% M/
@^T1XX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _~piZmkG$
{ 5\e9@1Rc
sSiteURL= sURL; "tB;^jhRs
sFilePath = sPath; OU8Lldt
sFileName = sName; Wzw7tLY._
this.nSplitter = nSpiltter; ,QcF|~n
=K6($|'=
XzIl`eH
} j#+!\ft5
Fxm$9(Y
1UE6 4Kl:S
public String getSSiteURL() dYL"h.x
{ (+B5|_xQu
return sSiteURL; =>M^02"
} r7b1-
5*1D$mxD"
+R|z{M)*
public void setSSiteURL(String value) ; mZW{j
{ !4^C #{$
sSiteURL = value; m^bNuo
} VzY8rI
K?BOvDW"`
',:*f8Jk
public String getSFilePath() `[W[H(AjQ
{ h"_MA_]~
return sFilePath; 1(|'WyD
} 8$0rR55
\3pc"^W
/7}It$|nhy
public void setSFilePath(String value) [[;e)SoA
{ 6f\Lf?vF
sFilePath = value; U-R6xxPZ
} `QyO`y=?[Y
{&\jW!&n
=5kY6%E7c
public String getSFileName() Mz~M3$$9n
{ Of4^?` ^
return sFileName; "x3lQ
} )XYv}U
fSs4ZXC
p$PKa.Y3
public void setSFileName(String value) X)7x<?DAy
{ 0l-Ef1
sFileName = value; {\c(ls{
} J2'Nd'
WJ4li@T7V
`/EGyN6X
public int getNSplitter() A^)?Wt%*
{ 0V'nK V"|
return nSplitter; Mf&{7%
} kPF9Z "l
]%?YZn<{
G>1eFBh }
public void setNSplitter(int nCount) FW/W%^
{ t.`@{R$hoA
nSplitter = nCount; `bZ/haU}A
} kw"SwdP5
} >g+?Oebgw
Y#u}tE d
%<an9WMF
/* }j*KcB_
**Utility.java r=X}%~_8X
*/ qoj$]
package NetFox; S"OR%
rdJ d#S
1n:8s'\
public class Utility { ?<(m 5Al7
[^U#Qj)hL
d5D$&5Ec
public Utility() n&-qaoNl
{ ?34 e-
iVy7elT;R
V`bi&1?6\
} 5A sP5
,!7 H]4Qx
//线程睡眠 `"&da#N]
public static void sleep(int nSecond) h $L/<3oP6
{ ;uwRyd
try{ ]cGA~d
Thread.sleep(nSecond); A7%:05
} t4-pM1]1_
catch(Exception e) XVvK2(
{ k;w- E
e.printStackTrace (); .)<(Oj|4
} rz@=pR :
} -lhLA`6_R
WC.t_"@
//日志 kX>f^U{j
public static void log(String sMsg) Y0_),OaY
{ )FpZPdN+h
System.err.println(sMsg); q.2ykL
} 3>R#zJf
%=/)
~Uxsn@nLr
public static void log(int sMsg) uoXAQ6k
{ L7VG`h;
System.err.println(sMsg); \>7^f 3m
} {|1Y:&M?
} .8y3O]
F@<CsgKB-
ad:&$
/* 49w=XJ
**TestMethod.java Ee3hG2d`
*/ op6CA"w
package NetFox; 1. rj'
L(khAmm
l PK +$f$
public class TestMethod { ,=|ZB4HA
+ j W1V}h
,B0_MDA +
public TestMethod() iv>SsW'p_
{ ///xx/weblogic60b2_win.exe il \$@Bn
try{ \'CDRr"uw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2EfF=Fm>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Oh'Y0_oB>
SiteFileFetch fileFetch = new SiteFileFetch(bean); AKRTBjG"
fileFetch.start(); e(I=^#u6
} hrhb!0
catch(Exception e){e.printStackTrace ();} Xt#4/>dlR
&9"-`-[e:
}b0; 0j
} <_XWWT%
8`fjF/
4qYUoCR&
public static void main(String[] args) I;Bjfv5
{ UGuxV+Nwf
new TestMethod(); x >^Si/t
} QCX8IIHG
} cdG|m[
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