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)); WyO10yvR
} d#A.A<p*
for(int i=0;i<nEndPos.length-1;i++) uRp-yu[nt%
{ D VC};
nEndPos = nStartPos[i+1]; uv Z!3UH.
} ;]'mx
nEndPos[nEndPos.length-1] = nFileLength; cm-!6'`
} 4Sw)IU~K(
} -l^u1z
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w%`7,du|
//启动子线程 VJm).>E3k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0*+i~g,Kl@
for(int i=0;i<nStartPos.length;i++) 8*lVO2
{ IY+P Yad
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HD$W\P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rBT#Cyl
nStartPos,nEndPos,i); `2}Mz9mk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z#*fELV
fileSplitterFetch.start(); xMU4Av[{
} YQ;?N66
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7RDfhKdb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L%Me wU0TZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fyh9U_M);w
nEndPos = " + nFileLength); fgq#Oi}
// fileSplitterFetch[nPos.length-1].start(); N<9CV!_
+Y6=;*j$
+AO(e
//等待子线程结束 ]~GwZB'M
//int count = 0; KP%A0
//是否结束while循环 4Y;z46yM%
boolean breakWhile = false; +q6/'ErN]m
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while(!bStop) }f/ 1
{ !T!U@e=u
write_nPos(); 2ntL7F<ow
Utility.sleep(500); JN,4#,
breakWhile = true; wL\OAM6R
=# <!s!
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for(int i=0;i<nStartPos.length;i++) `O5wM\Z
{ k+t?EZ6L
if(!fileSplitterFetch.bDownOver) -c{O!z6sX
{ *2P%731n5
breakWhile = false; ,( u-x!
break; gY|f[M|
} Nawph
} ark~#<SqAr
if(breakWhile) aJdd2,e
break; db -h=L|
&{-r 5d23
P{-j^'y
//count++; IOhJL'r
//if(count>4) P;4Y%Dq~Qo
// siteStop(); $KHw=<:)/
} Vsw]v
W|'7)ph
nvY%{Zf$}
System.err.println("文件下载结束！"); b~>kTO
} 'guXdX]Gu
catch(Exception e){e.printStackTrace ();} UTwXN |'|
} w`KqB(36
<;kcy :s
=S+*=jA
//获得文件长度 ut j7"{'k|
public long getFileSize() S#Q0aGj
{ {G.W?
int nFileLength = -1; >-oB%T
try{ MD|T4PPz,}
URL url = new URL(siteInfoBean.getSSiteURL()); lDsT?yHS`Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *^aEUp6&
httpConnection.setRequestProperty("User-Agent","NetFox"); ddK\q!0
hQ7-m.UZw
&X3G;x2;
int responseCode=httpConnection.getResponseCode(); w}|XSJ!
if(responseCode>=400) A#7/,1h\
{ = y@*vl
processErrorCode(responseCode); u1 Z;n
return -2; //-2 represent access is error #ME!G/
} \3"jW1Wb
ZNDn! Sj
A4uKE"WE
String sHeader; `^v=*&
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+P! ibHfP
for(int i=1;;i++) TW?_fse*[
{ /O[<"Wcz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Iv eKk5W
//Utility.log(in.readLine()); {'8td^JEE
sHeader=httpConnection.getHeaderFieldKey(i); &zR\Rmpt
if(sHeader!=null) 2t7P| b~V1
{ "_^vQ1M]Z
if(sHeader.equals("Content-Length")) LUs)"ZAi|
{ `' .;U=mF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #Z. QMWq
break; 'kOkwGf!
} \OJam<hZ
} lfw|Q@
else I1pnF61U
break; efr9
} PZ>(cvX&
} Q&#Arph0e
catch(IOException e){e.printStackTrace ();} yJK:4af;.
catch(Exception e){e.printStackTrace ();} G{.[o6>
G! Y l0Zr
I A%ZCdA;
Utility.log(nFileLength); -aq3Lqi
z+Guu8
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return nFileLength; 4Ei8G]O $_
} ^Gi7th,
KpBOmXE
6:~<L!`&
//保存下载信息（文件指针位置） S{m:Iij[;
private void write_nPos() K0WX($z~;
{ ;`O9YbP#
try{ tQ*?L
output = new DataOutputStream(new FileOutputStream(tmpFile)); GrUpATIx
output.writeInt(nStartPos.length); 4bCA"QM[[
for(int i=0;i<nStartPos.length;i++) fig~z=m
{ {,!!jeOO
// output.writeLong(nPos); :_,a%hb+8
output.writeLong(fileSplitterFetch.nStartPos); 2"T b><^"
output.writeLong(fileSplitterFetch.nEndPos); D<hX%VJ%M
} znB+RiV8
output.close(); blLl1Ak
} 2TG2<wqvE
catch(IOException e){e.printStackTrace ();} e*}*3kw)T
catch(Exception e){e.printStackTrace ();} L@'2}7N1%
} /d+v4GIB
;m7~!m)
Vm?#~}T
//读取保存的下载信息（文件指针位置） r$v\\^?2
private void read_nPos() /!JxiGn
{ ce;$)Ff\
try{ &.(iS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >z~_s6#CP
int nCount = input.readInt(); QLU <%w:B
nStartPos = new long[nCount]; -Bq]E,Xf)
nEndPos = new long[nCount]; =;GmLi3A
for(int i=0;i<nStartPos.length;i++) a x)J!I18
{ :f:&B8
nStartPos = input.readLong(); M,W-,l ]
nEndPos = input.readLong(); BL~#-Mm<|l
} |)xWQ KzA
input.close(); C?k\5AzT
} _X
catch(IOException e){e.printStackTrace ();} [ #ih o(/
catch(Exception e){e.printStackTrace ();} pHx$
} <2oMk#Ng^
;jaugKf
~Ad2L*5S
private void processErrorCode(int nErrorCode) sPb}A$'
{ Q>$lf.)
System.err.println("Error Code : " + nErrorCode); U.V/JbXX
} H5#]MOAP
(,ik:j
2D:,(
//停止文件下载 =>lX brJ
public void siteStop() g-jg;Ri
{ 5Ok3y|cEx
bStop = true; q6*i/"mN*
for(int i=0;i<nStartPos.length;i++) 3.Yg3&"Z
fileSplitterFetch.splitterStop(); k q]E@tE*3
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E<}sGzMc
} zR'EQ
} mR|5$1[b
//负责部分文件的抓取 u,nn\>Y
**FileSplitterFetch.java T{^P
*/ VwRZgL
package NetFox; _;0RW
,;5%&T
mI{Fs|9h
import java.io.*; eub}+~_?[
import java.net.*; Qe7=6<
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public class FileSplitterFetch extends Thread { A`JE(cIz3
5-ED\-
fzw:[z:%
String sURL; //File URL QZG<sZ0"
long nStartPos; //File Snippet Start Position 8X.= 6M
long nEndPos; //File Snippet End Position ^fe,A=k~1
int nThreadID; //Thread's ID xo?'L&%
boolean bDownOver = false; //Downing is over !;mn]wR>a
boolean bStop = false; //Stop identical :*h1ik4t
FileAccessI fileAccessI = null; //File Access interface ^n<YO=|u
x7<NaMK\
%.u*nM7sos
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]LZ#[xnM7
{ 9d^m 7}2
this.sURL = sURL; +6l#hO7h
this.nStartPos = nStart; M;b3- i
this.nEndPos = nEnd; @[?ZwzY:9
nThreadID = id; #]5KWXC'~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [zm@hxym
} 2A@oa9
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+ctU7 rVy
public void run() 0{%@"Fb0O
{ $0K@=7ms
while(nStartPos < nEndPos && !bStop) mD.6cV
{ {4A,&pR
7g]mrI@
uq-`1m}
try{ WA1d8nl
URL url = new URL(sURL); Li|~%E1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oy#(]K3`O
httpConnection.setRequestProperty("User-Agent","NetFox"); )-1e}VF(U
String sProperty = "bytes="+nStartPos+"-"; QD{1?aY
httpConnection.setRequestProperty("RANGE",sProperty); zj] g^c;
Utility.log(sProperty); ;`Xm?N
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InputStream input = httpConnection.getInputStream(); ]S]W|m7=.Z
//logResponseHead(httpConnection); %X.g+uu
2]9 2J
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byte[] b = new byte[1024]; _V1:'T8
int nRead; 'dh{q`#0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 13Z,;YW
{ EATVce]T
nStartPos += fileAccessI.write(b,0,nRead); <`=Kt[_BQ
//if(nThreadID == 1) r ~UDK]?V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =v::N\&
} x=xo9wEg
&dWGa+e
R31Z(vY
Utility.log("Thread " + nThreadID + " is over!"); XC~"T6F
bDownOver = true; "5k6FV
//nPos = fileAccessI.write (b,0,nRead); a}f/<-L
} ^yc8is'`
catch(Exception e){e.printStackTrace ();} 1;c>#20
} c CDT27@
} 7<)
BQ u8$W
fVY I
//打印回应的头信息 X)iI]
public void logResponseHead(HttpURLConnection con) o[ks-C>jw
{ XI[n!)3
for(int i=1;;i++) ^?(#%~NS
{ MK/8<i<.
String header=con.getHeaderFieldKey(i); 'Z.C&6_
if(header!=null) [o(!/38"@=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C@:X9NU
Utility.log(header+" : "+con.getHeaderField(header)); nXhP ME
else 2bw), W
break; Hc>yZ:c;
} ke;=Vg|
} b+ycEs=_
nt()UC`5
`W+-0F@Y?@
public void splitterStop() {.e+?V2>_
{ hg0{x/Dgny
bStop = true; { ?jXPf
} )SZ#%OE*
BxV>s+o&]
)7+z/y+[n
} 6XZjZ*)W
LVdR,'lS
fB7Jx6
/* wL:7G
**FileAccess.java yevJA?C4 v
*//文件访问(定位，写) WFk%nO/
package NetFox; %vZHHBylu
import java.io.*; k\SqDmv
BGj!/E
(gVN<Es
public class FileAccessI implements Serializable{ zvq}7,
RR+kjK?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w[3a^
RandomAccessFile oSavedFile; }{@y]DcdM4
long nPos; D{\o*\TN
l8+)Xk>
U" 3L
public FileAccessI() throws IOException ',]Aj!q
{ ,66(*\xT
this("",0); jwLZC
} oO3^9?Z
t$t'{*t( T
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public FileAccessI(String sName,long nPos) throws IOException W"vkmk
{ 8Ara^Xh}q
oSavedFile = new RandomAccessFile(sName,"rw"); *}#HBZe(9
this.nPos = nPos; r9M3rj]
oSavedFile.seek(nPos); [ypE[
} "m6G;cv
\zk>cQ
8mdVh\i!Kf
public synchronized int write(byte[] b,int nStart,int nLen) q&?hwX Z7
{ r 20!
int n = -1; <zTz/Hk`
try{ (7!pc
oSavedFile.write(b,nStart,nLen); [9 :9<#?o^
n = nLen; 7CF>cpw
} gsi2
catch(IOException e) \/SOpC
{ zx:;0Z:S6>
e.printStackTrace (); ZRw^< +
} ~(tt.l#
dD39?K/
yk4py0xVl
return n; $39TP@?:Z)
} *w^!\
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} iI'ib-d
e&ZH 1^O
jp~Tlomp
/* Yg&/^
**SiteInfoBean.java ZR)M<*$
*/ z.)*/HGJm
package NetFox; !U2<\!_
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T.;U~<
public class SiteInfoBean { =I&BO[d
K+L9cv4 |*
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private String sSiteURL; //Site's URL vg X7B4
private String sFilePath; //Saved File's Path "9Q_lVI|Q
private String sFileName; //Saved File's Name Cl&)#
private int nSplitter; //Count of Splited Downloading File k'e1ZAn
$JBb] v8_
|7Z}#eP//
public SiteInfoBean() vF@|cTRR)
{//nSplitter的缺省值为5 /']`}*d
//default value of nSplitter is 5 y9@j-m&
this("","","",5); <pG 4g
} }9z$72;Qdq
zt|1tU:
l`X?C~JhJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `s=Z{bw
{ -<T>paE9
sSiteURL= sURL; xa?auv!
sFilePath = sPath; SjA'<ZX>TM
sFileName = sName; /=#~8
this.nSplitter = nSpiltter; l;aO"_E1m
&K=)YpT
, :KJ({wM
} ZN'B@E=p
A+\rGVNH'S
pD~."fb
public String getSSiteURL() !T~uxeZ/;
{ YF;2jl Nm
return sSiteURL; Gw6!cp|/
} j#p3<V S4
mmNn,>AO!
k"/}9[6:U5
public void setSSiteURL(String value) g*4^HbVxt
{ w; f LnEz_
sSiteURL = value; mpIR: Im
} l[WX77bp=
&f)pU>Di
!{g>g%2!
public String getSFilePath() %(\et%[]
{ pVjOp~=U
return sFilePath; i{HzY[
} t""Y -M
+j8-l-o
nx{X^oc8e
public void setSFilePath(String value) @lh]?|*[
{ {p(6bsn_#]
sFilePath = value; Q+U" %
} ?xQm_ 91X^
^O"o-3dte
LTb#1JC
public String getSFileName() 1u }2}c|
{ N{Pa&/V
return sFileName; S1i~r+jf
} ;_=dB[M
iE ,"YCK
nIUts?mB
public void setSFileName(String value) )fke;Y0
{ es$<Vkbp
sFileName = value; '|&?$g(\h
} +' .o
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@.QuIm8,
public int getNSplitter() a3 t||@v!
{ S09Xe_q
return nSplitter; *44E'Dxv
} 2kFP;7FO
t6%zfm
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public void setNSplitter(int nCount) *E/CNMn=E
{ A_.}-dzF
nSplitter = nCount; =u5( zaBe
} k& ]I;Aq
} 7VfPS5se
0(A&m ,
jhka;m
/* 7wbpQ&1_
**Utility.java ,@8*c0Y~<!
*/ 'FG@Rg(
package NetFox; X;dUlSi
v 5&8C
t"&qaG{
public class Utility { 'W p~8}i@
L5]uT`Twa
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public Utility() RJD(c#r$
{ DC'L-]#<
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7)x788Z6
} mqQC`Aqx:
}I~)o!N%7
//线程睡眠 'u:J "
public static void sleep(int nSecond) $< .wQ8:Q
{ edfb7prfTl
try{ [T2!,D.
Thread.sleep(nSecond); 9f3rMPVh(
} )!=X?fz,O
catch(Exception e) 4 :M}Vz-
{ !=vd:,
e.printStackTrace (); 2-@z-XKn
} FOSC#W9E
} .oe\wJS6
W!b'nRkq
//日志 |I=GI]I
public static void log(String sMsg) kOv37c'
{ Tl-Ix&37
System.err.println(sMsg); eOUEhpE
} T2ZN=)xZ1
##yH*{/&
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public static void log(int sMsg) EnYEAjX
{ 6'1Lu1w
System.err.println(sMsg); idY Xv)R
} mS &^xWPV
} 8MBvp*
[}?E,1Q3
3q0S}<h al
/* {[r}gS%
**TestMethod.java 9&OhCrxW-
*/ V6r*fEhrT_
package NetFox; &nwk]+,0W#
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public class TestMethod { Gs(;&fw
5DVSaI$ =
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public TestMethod() \_t[\&.a}
{ ///xx/weblogic60b2_win.exe j.SE'a_
try{ uB+:sX-L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p)*x7~3e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); | =tGrHL
SiteFileFetch fileFetch = new SiteFileFetch(bean); eZmwF@
fileFetch.start(); }n?D#Pk,
} Ap!i-E,"J
catch(Exception e){e.printStackTrace ();} *4[P$k$7
o:lMRP~
<O~ieJim
} He}"e&K
9PJnKzQ4
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public static void main(String[] args) jluv}*If
{ :Oi}X7\
new TestMethod(); '$q3Ze
} =wFl(Q6J
} L#`X;:
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