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)); -Wig k['v
} >B9rr0d0
for(int i=0;i<nEndPos.length-1;i++) XrvrN^'
{ LD5'4,%-
nEndPos = nStartPos[i+1]; xNONf4I:6J
} 4C2 Dwj
nEndPos[nEndPos.length-1] = nFileLength; WH/a#F
} Ylf6-FbF
} D~{)\;w^!
%:/;R_
!l&lb]Vcz
//启动子线程 0r@rXwz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G cbal:q
for(int i=0;i<nStartPos.length;i++) Zaj<*?\
{ d*G$qUiX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *[jaI-~S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m]%cNxS
nStartPos,nEndPos,i); |[V(u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =];FojC6I
fileSplitterFetch.start(); 1HZexV
} j@:LMR>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4SOj>(a#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]F_u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S !e0:
nEndPos = " + nFileLength); ]f\rB8k|&
// fileSplitterFetch[nPos.length-1].start(); o 1b#q/
8=e\^Q+
?@XO*|xkSk
//等待子线程结束 *7Mrng
//int count = 0; F%Xq}LMd
//是否结束while循环 (O&b:D/Y
boolean breakWhile = false; ;uJVY)7a
\GkcK$Y
6D+9f{~r
while(!bStop) @3G3l|~>
{ K>q,?x b
write_nPos(); $@<\$I2s
Utility.sleep(500); U-Iwda8v
breakWhile = true; J|>P,x#G
_Ih~'Y Fd
abK/!m[q
for(int i=0;i<nStartPos.length;i++) B^OhL!*tI
{ fGxa~Unx
if(!fileSplitterFetch.bDownOver) WT0U)x( m5
{ b :+ X3
breakWhile = false; F |GWYw'%
break; `aUA_"f
} i^W\YLE
} .d*vfE$
if(breakWhile) g,1\Gj%y
break; _7;#0B
ru U|
#8(@a Y
//count++; 1]qhQd-u
//if(count>4) C{,nDa?|
// siteStop(); d9^h YS{
} d2(n3Xf
4v{gc/g
t &ucqY
System.err.println("文件下载结束！"); B.{yf4a#L
} ](O!6_'d
catch(Exception e){e.printStackTrace ();} D4S>Pkv
} %++q+pa
QM$?}>:
@U9ov >E
//获得文件长度 Rk'pymap
public long getFileSize() Xh{EItk~oO
{ y@(U6ZOyx
int nFileLength = -1; +yYz;, \
try{ ?2i``-|Wa
URL url = new URL(siteInfoBean.getSSiteURL()); s5[ Cr"q7B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;+5eE`]a/L
httpConnection.setRequestProperty("User-Agent","NetFox"); 7[K$os5al
%8v?dB;>x`
Y/4B*>kl
int responseCode=httpConnection.getResponseCode(); :|Z*aI]9
if(responseCode>=400) Nc7YMxk'H
{ VMNihx0FJ
processErrorCode(responseCode); Y`_6Ny="
return -2; //-2 represent access is error p3-sEIw}Ru
} EBn7waBS
-yC},tK
_E1:3N|
String sHeader; .|rpj&>g
LsLsSV
eHv/3"Og
for(int i=1;;i++) ^y??pp<1J
{ e06r5%|.%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VJPt/Dy{
//Utility.log(in.readLine()); wWH5T}\
sHeader=httpConnection.getHeaderFieldKey(i); \_+d*hHF~
if(sHeader!=null) X2EC+<
{ &<~`?-c
if(sHeader.equals("Content-Length")) jfI|( P
{ N (43+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @NNN&%
break; V43|Ej}E
} u6D>^qF}@'
} ~UL;O\-b0
else f-3lJ?6
break; PsTwJLY
} qEywExdiu
} J0{0B=d;
catch(IOException e){e.printStackTrace ();} Er%nSH^"
catch(Exception e){e.printStackTrace ();} 0uj3kr?cv
k<AnTboa
QYg2'`(
Utility.log(nFileLength); x=9drKIw>
Q.!D2RZc
f>Ij:b`Z2
return nFileLength; =i `o+H
} oo/#]a
n}YRE`>D
[5,#p$R
//保存下载信息（文件指针位置） 7q(RQQp
private void write_nPos() k/*r2 C
{ g<tr |n
try{ -l^u1z
output = new DataOutputStream(new FileOutputStream(tmpFile)); oo<,hOv
output.writeInt(nStartPos.length); Bl(we/r
for(int i=0;i<nStartPos.length;i++) t.3b\RV[
{ l.FkX
// output.writeLong(nPos); uNLA/hL+n
output.writeLong(fileSplitterFetch.nStartPos); KecRjon~
output.writeLong(fileSplitterFetch.nEndPos); 8*lVO2
} %\CsP!
output.close(); P0|V1,)
} hX<0{pXM4
catch(IOException e){e.printStackTrace ();} }+,;wj~
catch(Exception e){e.printStackTrace ();} `vUilh ^c
} z#*fELV
>NK*$r8
kJ{X5&,_
//读取保存的下载信息（文件指针位置） EQMn'>
private void read_nPos() %[5hTf
{ s<aJ pi{n4
try{ $(G.P!/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }ob#LC,
int nCount = input.readInt(); XB^o>/|@S
nStartPos = new long[nCount]; ;QS-a
nEndPos = new long[nCount]; *ewE{$UpK
for(int i=0;i<nStartPos.length;i++) tpU[KR[-
{ bF<FX_}!s!
nStartPos = input.readLong(); +AO(e
nEndPos = input.readLong(); 0)+F}SyyD
} 7<=xc'*8t
input.close(); j$,:cN
} Qv|A^%Ub!
catch(IOException e){e.printStackTrace ();} 3D(/k%;)
catch(Exception e){e.printStackTrace ();} R8sj>.I9j
} 0M>+.}e+
4uwI=UUB
DFcgUEq
private void processErrorCode(int nErrorCode) bU7n1pzW,o
{ ol[
System.err.println("Error Code : " + nErrorCode); !T!U@e=u
} xhWWl(r`5
;3'ta!.c
:H@Q`g u
//停止文件下载 lmfvT}$B
public void siteStop() GU([A@;
{ z;J"3kM
bStop = true; }CIH1q3P
for(int i=0;i<nStartPos.length;i++) A_i=hj2f
fileSplitterFetch.splitterStop(); 9rf6,hF
'H0uvvhOp
il|e5TD^
} )w4i0Xw^C:
} V9mqJRFJ:
//负责部分文件的抓取 (p>?0h9[
**FileSplitterFetch.java TgoaEufS<
*/ ]ri5mnB
package NetFox; qs6r9?KP
Yw7txp`i
Nawph
import java.io.*; bbCH(fYbu
import java.net.*; 6j/g/!9c!
F0(P2j
JZ3CCf
public class FileSplitterFetch extends Thread { rO[cm}
9J+p.N
~4fUaMT
String sURL; //File URL ;SnpD)x@)
long nStartPos; //File Snippet Start Position 4YX/=
long nEndPos; //File Snippet End Position /H3z~PBa
int nThreadID; //Thread's ID 1DLAfsLlj
boolean bDownOver = false; //Downing is over 6V-u<FJ
boolean bStop = false; //Stop identical q!iSY
FileAccessI fileAccessI = null; //File Access interface :#7"SEud}
e ?sMOBPlv
nvY%{Zf$}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \MI2^JN
{ v#c'p^T
this.sURL = sURL; Td(eNe_4T
this.nStartPos = nStart; &6wD
this.nEndPos = nEnd; W T~UEK'
nThreadID = id; 79`OB##
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1 etl:gcEC
} PDQEI55
XB0G7o%1
ut j7"{'k|
public void run() Fj;];1nt
{ H{M7_1T
while(nStartPos < nEndPos && !bStop) G5A:C(r
{ \no6]xN;
RGg=dN
Rxb?SBa
try{ 3u[m? Vw
URL url = new URL(sURL); lDsT?yHS`Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nQ*9E|Vx
httpConnection.setRequestProperty("User-Agent","NetFox"); X\4d|VJ?m
String sProperty = "bytes="+nStartPos+"-"; ddK\q!0
httpConnection.setRequestProperty("RANGE",sProperty); iq1HA.X(
Utility.log(sProperty); .bYZkO:oy
/{Mo'.=Z
03pD<
InputStream input = httpConnection.getInputStream(); Jt++3]
//logResponseHead(httpConnection); -d>2&)5
yxk:5L \A
%B}<5iO
byte[] b = new byte[1024]; >^:*x_a9
int nRead; G.")Bg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |#(KP
{ A:b(@'h
nStartPos += fileAccessI.write(b,0,nRead); 1aAY7Dm_&
//if(nThreadID == 1) I%(YR"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NTWy1
} (/gv U80
0Wkk$0h9
,ArHS
Utility.log("Thread " + nThreadID + " is over!"); \<ko)I#%
bDownOver = true; / <C{$Gu
//nPos = fileAccessI.write (b,0,nRead); IN8G4\r
} lQl!TW"aO
catch(Exception e){e.printStackTrace ();} )2sE9G,
} S2i*Li
} q]scKWYI
^yLhL^Y
/PZx['g
//打印回应的头信息 v*";A
public void logResponseHead(HttpURLConnection con) g?.y7!m
{ ]SC|%B_*
for(int i=1;;i++) R?t_tmKXC!
{ <uYrYqN
String header=con.getHeaderFieldKey(i); 4%B0H>
if(header!=null) #Z. QMWq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o;TS69|D
Utility.log(header+" : "+con.getHeaderField(header)); VQ"Z3L3-4
else !n7'TM'
break; CZ33|w
} Kpg?' !I
} ty8>(N(~
,B~5;/|
57wHo[CJ
public void splitterStop() 'aWqj+Wbh
{ **V8a-@
bStop = true; n!dXjInV
} yJK:4af;.
R 7h^ @
[I?[N.v
} G! Y l0Zr
,&~-Sq)~
Ij>G7Q*d
/* A`~R\j
**FileAccess.java i/.#`
*//文件访问(定位，写) =,b6yV+$D
package NetFox; R-Ys<;
import java.io.*; Q7.jSL6
2YDD`:R
w}]BJ<C
public class FileAccessI implements Serializable{ Sse%~:FL
7@&mGUALO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9^u}~e #(
RandomAccessFile oSavedFile; J8-K
long nPos; 7W'&v+\
`?{6L#
q`'m:{8
public FileAccessI() throws IOException F EUfskv
{ AGl#f\_^
this("",0); /X]gm\x7s
} s~QIs
/Y=_EOS
s3Wjhw/
public FileAccessI(String sName,long nPos) throws IOException #<~oR5ddlb
{ ZZw2m@T>
oSavedFile = new RandomAccessFile(sName,"rw"); ~:L5Ar<
this.nPos = nPos; #Iu"qu
oSavedFile.seek(nPos); S{RRlR6Z
} ,.kmUd
QOX'ZAB`
<5E)6c_W)
public synchronized int write(byte[] b,int nStart,int nLen) :>}7^1I
{ @SH[<c
int n = -1; &q&~&j'[
try{ $Zr \$z2
oSavedFile.write(b,nStart,nLen); &pQ[(|=(
n = nLen; h3bQ<?m
} 7'OR;b$
catch(IOException e) b# Dd
{ {Q>4zepN!
e.printStackTrace (); >k ==7#P
} cTz@ga;!mI
yEMM@5W)8
^*YoNd_kpN
return n; LF`]=.Q
} JMk2OK{0
8[.&ca/[
dt@~8kS
} NT2XG&$W>
kh@O_Q`j
s2(7z9jR
/* ALn_ifNh
**SiteInfoBean.java !rs }83w!
*/ ]cv/dY#
package NetFox; nrA 4N1
ZeY|JH1
z;?ztpa@
public class SiteInfoBean { CDF;cM"td
,{\Ae"{6
aS[y\9(**
private String sSiteURL; //Site's URL '%ByFZzi
private String sFilePath; //Saved File's Path +1I7K|M
private String sFileName; //Saved File's Name "Bv V89
private int nSplitter; //Count of Splited Downloading File :IU<AG6
Z t4q= Lr
Buso `G
public SiteInfoBean() \crh`~?>
{//nSplitter的缺省值为5 j\wZjc-j
//default value of nSplitter is 5 p0y|pD
this("","","",5); $tF\7.e@
} ~3-"1E>Rgy
RX%)@e/@
nGwon8&]]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U.V/JbXX
{ *P5\T4!+d
sSiteURL= sURL; O8A(OfX
sFilePath = sPath; (,ik:j
sFileName = sName; +=Q:g,kP
this.nSplitter = nSpiltter; -+u}u=z%
,;hpqu|
1JUje
} r*8a!jm?
o=#ym4hJ%
Pwj|]0Y@
public String getSSiteURL() S(U9Dlyarg
{ #>HY+ ;
return sSiteURL; ~ o2Z5,H
} j/Y]3RSMp
WVsj
=L@CZ"
public void setSSiteURL(String value) E24SD'|)
{ U}4I29M
sSiteURL = value; WUjRnzVM
} }Xk_ xQVt{
(,t[`z
tBfmjxv
public String getSFilePath() "g)bNgGV}
{ ',!jYh}Uxk
return sFilePath; OiXO<1'$
} .gGO+8[N*
mn=b&{')e
oH&@F@r:+
public void setSFilePath(String value) eub}+~_?[
{ [mQ1r*[j
sFilePath = value; aeI0;u
} \2=I//YF
m&b1H9ymd
0:n"A,-p
public String getSFileName() "f<gZsb
{ R2?s NlF
return sFileName; )iiaT~ ]
} 5M~+F"Hl
,?Ie!r$6
l5=ih9u
public void setSFileName(String value) wkPjMmW+!
{ ItvcN
sFileName = value; yH]Q;X'
} K!qOO
]" e'z
JIw?]xa*
public int getNSplitter() MRXw)NAw
{ >q&5Z
return nSplitter; ^n<YO=|u
} U^|T{g+O
U}DE9e{/!
%FM26^
public void setNSplitter(int nCount) fMUh\u3
{ #"~\/sb
nSplitter = nCount; G u_\ySV/y
} &*'^uCna
} P7zUf
6M`gy|"(~
)eT>[['fm
/* ?H,f|nc
**Utility.java vf@j d}?
*/ 1$.svR
package NetFox; ;+(_stxqV9
&4KUXn[F
64#Ri!RR}
public class Utility { 1kpw*$P0
Nu?A>Q
[e ztu9
public Utility() ,wM}h
{ |a"]@W$>
.)+c01
.tGz,z}
} vV$t`PEY
LQr!0p.i"
//线程睡眠 RCYv2=m>Q
public static void sleep(int nSecond) 6nE/8m
{ ?D2a"a$^
try{ <XG]aYBR
Thread.sleep(nSecond); 9 Xl#$d5
} 6{^\7`
catch(Exception e) +D4m@O
{ CmbgEGIh[a
e.printStackTrace (); Xe_djy'8
} QwpX3 k6
} 'h0>]A 2|X
:<B_V<
//日志 $z*"@
public static void log(String sMsg) axt;}8
{ ]S]W|m7=.Z
System.err.println(sMsg); 8rS;}Bt
} e(a,nZF.
2]9 2J
|n tWMm:(
public static void log(int sMsg) ^7? WR?!
{ _V1:'T8
System.err.println(sMsg); $\vNSTE
} ,{S $&g*
} "ldd&><
%Rf9KQ
60{DR >S
/* cf$ hIB)Oi
**TestMethod.java /3rNX}tOMH
*/ 1Dc6v57
package NetFox; KMkD6g
RD)Vb$.B:
u0arJU_.)
public class TestMethod { CUG"2K9
/bo=,%wJ[
b\H&E{Gn|x
public TestMethod() (M1YOK)I
{ ///xx/weblogic60b2_win.exe <F&XT@
try{ *A8*FX>\F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6@/k|t>OT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7- LjBlH
SiteFileFetch fileFetch = new SiteFileFetch(bean); i~v[3e9y7
fileFetch.start(); WHv6E!^\_
} xrBM`Bj0@
catch(Exception e){e.printStackTrace ();} bcy
%5zIh[!1$
@w.DN)GPo
} L>1y[ Q
XI[n!)3
/1{:uh$
public static void main(String[] args) )h 6w@TF
{ ?.F^Oi6 u
new TestMethod(); uQn1kI[y
} n!~ $Z/
} 8]vut{
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