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)); }ikJa
} F^)SQ%xx
for(int i=0;i<nEndPos.length-1;i++) 1X$hwkof
{ 2Ed
nEndPos = nStartPos[i+1]; c<n <!!vi
} {9yW8&m
nEndPos[nEndPos.length-1] = nFileLength; #}U*gVYe
} c<J/I_!
} FZW:dsm
g4fe(.?c,
f}U@e0Lsb
//启动子线程 }9,^=g-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z UCz-53
for(int i=0;i<nStartPos.length;i++) >!7\Rx
{ -F+dmI,1$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qqR8E&Y{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [#hoW"'Q9
nStartPos,nEndPos,i); t)hAD_sf
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 95%, 8t
fileSplitterFetch.start(); si|DxDx
} $7bl,~Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), js#72T/_n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z(=UZI?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zjVQ\L
nEndPos = " + nFileLength); |-SImxV
// fileSplitterFetch[nPos.length-1].start(); L[s8`0
|#6))Dh
I/ q>c2Pw$
//等待子线程结束 u:FFZ
//int count = 0; 0nbQKoF
//是否结束while循环 LAT%k2%Wx
boolean breakWhile = false; jQc.@^#+x
&bO5+[
@h&crI[c
while(!bStop) 9gLUM$Kd
{ DfJHH)Ry}
write_nPos(); w6 x{<d
Utility.sleep(500); :Vyr8+]
breakWhile = true; ;F:~HrxT}
keYvscRBI
)GpH5N'EI
for(int i=0;i<nStartPos.length;i++) U=a'(fX
{ zAxscDf'
if(!fileSplitterFetch.bDownOver) ]$VYzE2e
{ b+g(=z+
breakWhile = false; x/pM.NZF1
break; v_$'!i$
} .%'$3=/oe
} |QIFtdU5T
if(breakWhile) wf= s-C
break; fuQb h
N4wv'OrL]
<e s>FD
//count++; BV8-\R@
//if(count>4) Z?#_3h$"T
// siteStop(); )TmqE<[
} S-8wL%r
opKk#40
.=nx5yz
System.err.println("文件下载结束！"); .[E"Kb}=
} k[6xuyY]
catch(Exception e){e.printStackTrace ();} H)Zb_>iV
} soH M5<U
9<9 c^2
Dj~]]
//获得文件长度 99\;jz7
public long getFileSize() TaZw_)4c
{ h#o3qY
int nFileLength = -1; .!kO2/:6
try{ `o.DuvQ E
URL url = new URL(siteInfoBean.getSSiteURL()); U8T"ABvFP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >z`^Q[
httpConnection.setRequestProperty("User-Agent","NetFox"); WCg*TL}
P?y3YxS
~1NK@=7T
int responseCode=httpConnection.getResponseCode(); *6-fvqCv
if(responseCode>=400) b&y"[1`
{ J< E"ZoY
processErrorCode(responseCode); C;T:'Uws
return -2; //-2 represent access is error nj (/It
} *q?-M"K
|HjoaN)
=9lrPQ]w
String sHeader; 3c"$@W:>
5&y;r
PjH[8:,
for(int i=1;;i++) fjE
{ 3 e19l!B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >d`XR"_e
//Utility.log(in.readLine()); $Vi[195]2
sHeader=httpConnection.getHeaderFieldKey(i); sg.8Sd"]7
if(sHeader!=null) 8$|<`:~J
{ e~#"#?
if(sHeader.equals("Content-Length")) %~V+wqu
{ >t[beRcR6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g1je':
break; ]%{.zl!
} PY4RwN
} WcCJ;z:S?k
else r((2.,\Z
break; 6I$laHx?
} {*=+g>RgD
} M~0A-*N
catch(IOException e){e.printStackTrace ();} j.3#rxq
catch(Exception e){e.printStackTrace ();} *H"IW0I
ArFsr
~*3obZ2>2
Utility.log(nFileLength); fpjy[$8
&=1Ag}l57
0!D,74r
return nFileLength; h>'9-j6B
} A@8Ot-t:\2
&C~R*
y:U'3G-
//保存下载信息（文件指针位置） LQ,RQ~!
private void write_nPos() thoAEG80
{ jV(\]g"/=
try{ DCJmk6p%0
output = new DataOutputStream(new FileOutputStream(tmpFile)); _RLx;Tn)L
output.writeInt(nStartPos.length); ugtzF
for(int i=0;i<nStartPos.length;i++) 2Xu?/yd
{ ? m$uqi
// output.writeLong(nPos); O*hd@2hd
output.writeLong(fileSplitterFetch.nStartPos); e&Z\hZBb
output.writeLong(fileSplitterFetch.nEndPos); zW`Zmt\T2
} =h?Q.vad
output.close(); R&w2y$
} 0p8Z l
catch(IOException e){e.printStackTrace ();} "6T: &>
catch(Exception e){e.printStackTrace ();} *WSH-*0
} T6X%.tR>`
R^%uEP
'~dE0ohWb
//读取保存的下载信息（文件指针位置） UbBo#(TZ)
private void read_nPos() Bg^k~NX%
{ fI{ZElPp
try{ x^UE4$oo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #n=b*.
int nCount = input.readInt(); KY)rkfo B
nStartPos = new long[nCount]; ?e? mg
nEndPos = new long[nCount]; / 38b:,
for(int i=0;i<nStartPos.length;i++) 8>:kv:MId
{ 3pxm0|
nStartPos = input.readLong(); =1dU~B:Lm
nEndPos = input.readLong(); traJub
} +O<0q"E
input.close(); /Q7cQ2[EU
} 9NH"Ik*
catch(IOException e){e.printStackTrace ();} KFCL|9P
catch(Exception e){e.printStackTrace ();} S ("Zzq`
} +/A`\9QT
+k!Y]_&(:f
RB5fn+FiZ
private void processErrorCode(int nErrorCode) jB8n\8Bs
{ )I80Nq
System.err.println("Error Code : " + nErrorCode); Ua.7_Em
} FHNK%Ko
>Z#=<
` [ EzU+
//停止文件下载 32_{nLV$[
public void siteStop() xl%!7?G|$>
{ )7mX]@
bStop = true; O*3x'I*a
for(int i=0;i<nStartPos.length;i++) 20hF2V
fileSplitterFetch.splitterStop(); 1'5I]D ec
`{g8A P3
Gt&x<
} K\ww,S
} "ei*iUBN:
//负责部分文件的抓取 +):t6oX|
**FileSplitterFetch.java <!.'"*2
*/ J@ x%TA
package NetFox; R5LzqT,/N:
*|n::9
nZ>bOP+,
import java.io.*; gY AXUM,
import java.net.*; %?^T^P
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,63hO.4M
public class FileSplitterFetch extends Thread { Wxl^f?I`:
NiU}A$U
.O[RE_j
String sURL; //File URL q<>
long nStartPos; //File Snippet Start Position u,0N[.&N
long nEndPos; //File Snippet End Position F]~rA! g1
int nThreadID; //Thread's ID !dfc1UjB
boolean bDownOver = false; //Downing is over -If-c'"G
boolean bStop = false; //Stop identical `"v5bk
FileAccessI fileAccessI = null; //File Access interface N=K|Nw
*F+t`<2
66<3zadJZU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qu[ ~#
{ dzZ74FE!t
this.sURL = sURL; o+W5xHe^1
this.nStartPos = nStart; ]trVlmZXH}
this.nEndPos = nEnd; 4l2i'H
nThreadID = id; 3X$)cZQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @NGK2J
} 8~?3: IZ
kVs'>H@FY
<}b`2/wP
public void run() ;crQ7}k
{ ryzz!0l
while(nStartPos < nEndPos && !bStop) I0 a,mO;m
{ 5EDN 9?a
X3#/|>
*6~ODiB
try{ TEl:;4
URL url = new URL(sURL); LRBcW;.Su
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pN/)$6=
httpConnection.setRequestProperty("User-Agent","NetFox"); R6~x!
String sProperty = "bytes="+nStartPos+"-"; !=@Lyt)_b
httpConnection.setRequestProperty("RANGE",sProperty); O(;K]8
Utility.log(sProperty); m"\jEfjO
z]ZhvH7-
7''l\3mIn
InputStream input = httpConnection.getInputStream(); 6Y6DkFdvrZ
//logResponseHead(httpConnection); iph>"b$D
v5l)T}Nb
%pgie"k
byte[] b = new byte[1024]; tVd\r"0k
int nRead; pfgFHNH:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R*IO%9O
{ 7PO3{I
nStartPos += fileAccessI.write(b,0,nRead); 5<bc>A-
//if(nThreadID == 1) |cStN[97%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |;_NCy8i3X
} #k8bZ?*:
<qN0Q7
V{;!vt~
Utility.log("Thread " + nThreadID + " is over!"); {]<l|qK
bDownOver = true; 8*3o9$Pj
//nPos = fileAccessI.write (b,0,nRead); !Uz{dFJf;
} \bqIe}3V7
catch(Exception e){e.printStackTrace ();} 0F-X.Dq
} %"PG/avo
} lxy_O0n
D'Tb=
n"8vlNeW
//打印回应的头信息 l CHaRR7
public void logResponseHead(HttpURLConnection con) k@U8K(:x
{ x@I*(I
for(int i=1;;i++) jZeY^T)f"
{ ~4h<nc
String header=con.getHeaderFieldKey(i); Nq1la8oQ3
if(header!=null) fyPpzA0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3Yf&F([t
Utility.log(header+" : "+con.getHeaderField(header)); ^%|,G:r
else GZ0? C2\
break; ]|62l+
} 1ael{b!
} 1>P[3Y@}
_#@n^c
b/'{6zn
public void splitterStop() lo*OmAF
{ k8H@0p
bStop = true; WV&T
} D/)wg$MI
,T@+QXh
)9F-h8 &"
} VZo[\sWf
1BT]_ cP
HA&7 ybl
/* +\g/KbV7
**FileAccess.java {T4F0fu[eR
*//文件访问(定位，写) }a?PBo`
package NetFox; F: %-x=q
import java.io.*; A>WMPe:sSS
i ,Cvnp6Lv
j8n_:;i*
public class FileAccessI implements Serializable{ s}Phw2`1U
Py*( %
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2N*XzVplN
RandomAccessFile oSavedFile; .nN=M>#/
long nPos; )!6JSMS
n%'M?o]DF
2gM=vaiH=
public FileAccessI() throws IOException V]I@&*O~r
{ ,/0Q($oz
this("",0); <xM$^r)
} LXYpP-E
yg({g "
<Sds5 d
public FileAccessI(String sName,long nPos) throws IOException U%%fKL=S
{ 9/A$3#wF
oSavedFile = new RandomAccessFile(sName,"rw"); l{b<rUh5W
this.nPos = nPos; 1ocd$)B|}
oSavedFile.seek(nPos); Q{%2Npvq
} 1 &G0;
8Aq [@i
FY;\1bt<<
public synchronized int write(byte[] b,int nStart,int nLen) k3[rO}>s
{ V~#e%&73FH
int n = -1; xPBSJhla
try{ /$NDH]a
oSavedFile.write(b,nStart,nLen); $ti*I;)h4
n = nLen; rP4v_?Zg+
} =^liong0
catch(IOException e) $DPMi9,7^
{ +'fy%/
e.printStackTrace (); ^RL#(O
} UI:YzR
9Z?P/ o
.'`7JU#{
return n; HCBZ*Z-
} x"g-okLN
v[$-)vs*ag
(<M^C>pldf
} %>,B1nt
'u9,L FO
@8keLrp
/* E`E$ }iLs
**SiteInfoBean.java Q1ox<-
*/ 1Yr&E_5/
package NetFox; m(2(Caz{
0[A4k:
QuF76&)7
public class SiteInfoBean { L >* F8|g
4Cd#S9<ed
!v/j*'L<M}
private String sSiteURL; //Site's URL ^pI&f{q
private String sFilePath; //Saved File's Path i4sd29v
private String sFileName; //Saved File's Name O &/9wi>!q
private int nSplitter; //Count of Splited Downloading File =1!,A
0<g;g%
CsJ38]=Mt
public SiteInfoBean() N3M:|D
{//nSplitter的缺省值为5 24Y8n
//default value of nSplitter is 5 /5x~3~
this("","","",5); @ve4rc/LI
} n jfh4}g:
}"$2F0
C(=$0FIR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g&79?h4UXQ
{ q+j.)e
sSiteURL= sURL; ywSV4ZtM
sFilePath = sPath; y15 MWZ
sFileName = sName; 0n FEPMO
this.nSplitter = nSpiltter; =)h<" 2
8LI aN}
;8|D4+
} rLkUIG
?MW*`U
mYU7b8x_
public String getSSiteURL() 5hhiP2q
{ S1Z~-i*w
return sSiteURL; Dw%V.J/&o
} >AtW
z;c~(o@4
*Ce8( "v,
public void setSSiteURL(String value) oVD)Fb%[i9
{ fbl8:c)I
sSiteURL = value; J|O=w(
} N5ph70#y3
[N35.O6P6u
A#b`{C~l
public String getSFilePath() k$ya.b<X/
{ wgN)*dpuI
return sFilePath; (f-Mm0%[
} *A^j>lV
wqB 5KxO
vb&1 S
public void setSFilePath(String value) zeC@!,lH
{ &J]|pf3m
sFilePath = value; 1X ?9Ji)h
} T>~D(4r|pS
~o<+tL
k=nN#SMn
public String getSFileName() u{asKUce\
{ JU6PBY~C'
return sFileName; ,qj1"e
} Y=NXfTc
I^u$H&
!ek};~(
public void setSFileName(String value) $i|c6&
{ &7fwYV
sFileName = value; i[+cNJ|$B0
} x5X;^.1Fr
$ ]fautQlt
nEG+TRZ)\
public int getNSplitter() oP"X-I
{ pv}k=wqJ1
return nSplitter; 5z T~/6-(
} SU`RHAo
,Ky-3p>
I7S#vIMXR.
public void setNSplitter(int nCount) 8V08>M
{ ^D}]7y|fm
nSplitter = nCount; cn3F3@_"\
} .{=|N8*py8
} [9lfR5=Xw[
2w7PwNb*32
hoDE*>i
/* wnPg).
**Utility.java `\pv^#5HV9
*/ O:I"<w9_1
package NetFox; ;1^([>|
nZtP!^#
zxo" +j4Ym
public class Utility { XMLJX~
8M~^/Zc
hi.`O+;
public Utility() $Ith8p~
{ L3@upb
d41DcgG'j(
HT% =o}y
} Pw:{
!#[=,'Y
//线程睡眠 w y\0o
public static void sleep(int nSecond) &hSABtr}
{ PL}c1Ud
try{ C-:lM1
Thread.sleep(nSecond); `p'(:W3a
} gR]NH
catch(Exception e) jI;iTKjB(
{ dsiQ~ [
e.printStackTrace (); e*Gt%'
} d OYEl<!J
} ]E:K8E
y+"6Y14
//日志 {~y,.[Ga
public static void log(String sMsg) ?r}'0dW
{ >Hd0l L
System.err.println(sMsg); h't!1u
} Y;uQq-CP
f7y3BWOi]
p3q >a<
public static void log(int sMsg) c*~/`lG
{ Pf/_lBtL
System.err.println(sMsg); >69-[#P!
} D00v"yp%%
} #JD:i%
Q/2(qD; u
"pa2,-&
/* 1I#]OY#>
**TestMethod.java Fo:60)Lr
*/ m(0c|-
package NetFox; d>wpG^"w
QrSF1y'd
a^xt9o`
public class TestMethod { Kwmtt
.VG5 / 6zp
N\nxo0sl
public TestMethod() T4fVZd)x
{ ///xx/weblogic60b2_win.exe n8RE
try{ ZdsYIRU#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /9o gg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YA:!ULzR*
SiteFileFetch fileFetch = new SiteFileFetch(bean); N, SbJ Z
fileFetch.start(); Pz77\DpFi
} +v{g'
catch(Exception e){e.printStackTrace ();} s)BB(vQ]6
:oeDksld
ui .riD[,O
} ?? 2x*l1
;QS(`SK l
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public static void main(String[] args) !+H)N
{ `iZ){JfAH
new TestMethod(); sogdM{tz\
} 7 /7,55
} 'Z}3XVZEN
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