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)); |pBFmm*
} :TP4f ?FA
for(int i=0;i<nEndPos.length-1;i++) R'tvF$3=i
{ A9@coP5
nEndPos = nStartPos[i+1]; !:5'MI@
} w@R"g%k-
nEndPos[nEndPos.length-1] = nFileLength; zfI{cMn'J
} HU/4K7e`
} bXOM=T
eP:\\; ;
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//启动子线程 X6Z/xb@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q{
for(int i=0;i<nStartPos.length;i++) ewn\'RLZ"@
{ Wf8@B#^{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BjPU@rS.U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jf1GYwuW*
nStartPos,nEndPos,i); PE6,9i0ee
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /^jl||'H,:
fileSplitterFetch.start(); =&k[qqxg
} 9pj6`5Zn@6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u@:[ dbJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h {Jio>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $Lbamg->E
nEndPos = " + nFileLength); zmD7]?|
// fileSplitterFetch[nPos.length-1].start(); OY81|N j
6 F39'
#+_=(J
//等待子线程结束 iuXXFuh
//int count = 0; }BT0dKx
//是否结束while循环 /CyFe<t
boolean breakWhile = false; f$5pp=s:n
o/a2n<4
R#y"SxD()
while(!bStop) Dpu?JF]
{ 98 NFJ
write_nPos(); vpT\CjXHZ
Utility.sleep(500); m*B4a9f
breakWhile = true; )f^^hEIS
#b)`as?!1
|N6.:K[`
for(int i=0;i<nStartPos.length;i++) K% snE7X?)
{ \Ezcr=0z{j
if(!fileSplitterFetch.bDownOver) 3rHn?
{ ' e!WZvr
breakWhile = false; hg<[@Q%$o
break; BUsxgs"),
} iyR"O1]
} {0+WVZ4u
if(breakWhile) pQc-}o"
break; fyT|xI`iD
JJg;X :p
-@]b7J?`k
//count++; 6!itr"
//if(count>4) ]LxE#R5V
// siteStop(); Ja&S_'P[
} &M3KJ I0L
GB}=
dP_bFUzg
System.err.println("文件下载结束！"); sz/^Ie-~
} W?wt$'
catch(Exception e){e.printStackTrace ();} 8_Uhh5[
} :t "_I
9(!AKKrr;
^[bFGKE
//获得文件长度 -O1$jBQS
public long getFileSize() ]n"RPktx
{ [742s]j
int nFileLength = -1; Nr*X1lJ6
try{ 0!0o[3*
URL url = new URL(siteInfoBean.getSSiteURL()); 2v@B7r4}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); umnQ$y 0
httpConnection.setRequestProperty("User-Agent","NetFox"); =w`uZ;l$Q
w 2U302TZ
Gl|n}wo$
int responseCode=httpConnection.getResponseCode(); B6Ajcfy
if(responseCode>=400) #l- 0$
{ q o^mp
processErrorCode(responseCode); ~UeTV?)
return -2; //-2 represent access is error a%kvC#B
} h*1T3U$
Np$&8v+en
o-l-Z|)7
String sHeader; D{y7[#$h$
H=~7g3
*[b>]GXd49
for(int i=1;;i++) 88S:E7 $
{ Y}2Sr-@u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P{QHG 3
//Utility.log(in.readLine()); Z1($9hE>
sHeader=httpConnection.getHeaderFieldKey(i); yw7(!1j=
if(sHeader!=null) 7hPwa3D^
{ / bH2Z
if(sHeader.equals("Content-Length")) aMHC+R1X
{ %-K5sIz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 84e8z{
break; -z-yk~F
} Os9EMU$
} C'gv#!Q
else f9kd&#O&
break; uHmvHA~/c8
} ,#GB
} "zXrfn
catch(IOException e){e.printStackTrace ();} rMjb,2*rC7
catch(Exception e){e.printStackTrace ();} 2&]LZ:(
)Qe]!$tqfD
I 2OQ
Utility.log(nFileLength); `T1bY9O.
=6=:OId
=v<A&4
return nFileLength; 0QfDgDX
} -Hw3rv3o
+%K~
vV9vB3K5?
//保存下载信息（文件指针位置） _&s pMf
private void write_nPos() 8qw{e`c
{ &?1^/]'"r
try{ olxxs(
output = new DataOutputStream(new FileOutputStream(tmpFile)); ln8NcAEx
output.writeInt(nStartPos.length); /2/aMF(J
for(int i=0;i<nStartPos.length;i++) 5=#d#dDc
{ emrA!<w!W
// output.writeLong(nPos); OA\]|2 :
output.writeLong(fileSplitterFetch.nStartPos); VMJaL}J]
output.writeLong(fileSplitterFetch.nEndPos); k%O3\q
} ]'Ho)Q
output.close(); OUGkam0UK
} h.ftl2>
catch(IOException e){e.printStackTrace ();} }KIS_krs
catch(Exception e){e.printStackTrace ();} fXl2i]L(^B
} C%]qK(9vvd
I"lzOD; eI
aTeW#:m
//读取保存的下载信息（文件指针位置） [ @"6:tTU
private void read_nPos() .%.7~Nu,
{ L'aB/5_%
try{ hp9LV2_5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7(tsmP
int nCount = input.readInt(); L1(-xNUo_i
nStartPos = new long[nCount]; U{pg y#/
nEndPos = new long[nCount]; xJ. kd Tr
for(int i=0;i<nStartPos.length;i++) A4#FAFy
{ N#e9w3Rli
nStartPos = input.readLong(); U\j g X
nEndPos = input.readLong(); u1#(~[.
} ?(K=du
input.close(); y6[le*T
} ]plp.f#av
catch(IOException e){e.printStackTrace ();} c@}t@k
catch(Exception e){e.printStackTrace ();} >ZG$8y 'j
} qsbo"29
w4TQ4 Y
'2<r{
private void processErrorCode(int nErrorCode) NqOX);'L0
{ (6a<{
System.err.println("Error Code : " + nErrorCode); &$_!S!Sa/
} +By'6?22
<)(W7#Ks
i}v.x
//停止文件下载 oS9Od8
public void siteStop() ZxT E(BQv
{ BQg3+w:>
bStop = true; .7b%7dQ<\
for(int i=0;i<nStartPos.length;i++) 9609
fileSplitterFetch.splitterStop(); DQXcf*R
Ny$3$5/
GQ@mQ=i
} .lP',hn
} VWHpfm[r%
//负责部分文件的抓取 UdnRsp9S
**FileSplitterFetch.java 6<fG;:
*/ Jkbeh.
package NetFox; e_KfnPY
M_ %-A
Khc^q*|C)
import java.io.*; gVzIEE25
import java.net.*; Tjrb.+cua
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"uIaKb
public class FileSplitterFetch extends Thread { YMK ![ q-
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~KkC089D
String sURL; //File URL #m?)XB^_
long nStartPos; //File Snippet Start Position 5toa@#Bc%
long nEndPos; //File Snippet End Position AL3iNkEa
int nThreadID; //Thread's ID J9]cs?`)
boolean bDownOver = false; //Downing is over <anKw|
boolean bStop = false; //Stop identical "H`Be
FileAccessI fileAccessI = null; //File Access interface rg>2tgA
F5/,S
Bh cp=#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZnI15bsDx
{ id5`YA$
this.sURL = sURL; gz[3xH~
this.nStartPos = nStart; J-dB
this.nEndPos = nEnd; g([:"y?
nThreadID = id; `=#jWZ.8m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A7+ZY,
} #*_!Xc9f
^w~B]*A:"
?-mOAHW0q
public void run() \DZ.#=d
{ MSvZ3[5Io
while(nStartPos < nEndPos && !bStop) s*yl&El/
{ +#BOWz
^ `Ozw^~
Sm4BZF~!B
try{ J({D~
URL url = new URL(sURL); 0]c&K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); llX `
httpConnection.setRequestProperty("User-Agent","NetFox"); ?%Nh4+3N>
String sProperty = "bytes="+nStartPos+"-"; [tfB*m5
httpConnection.setRequestProperty("RANGE",sProperty); OmBz'sp:
Utility.log(sProperty); -NN=(p!<
(iir,Ks2C
k"&o)*d
InputStream input = httpConnection.getInputStream(); TK\3mrEI
//logResponseHead(httpConnection); o68i0aFW
T pF[-fO
DWKQ>X6
byte[] b = new byte[1024]; *1`X}
int nRead; b1 w@toc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1s=Q~*f~d
{ !KK`+ 9/
nStartPos += fileAccessI.write(b,0,nRead); Y 2ANt w@
//if(nThreadID == 1) I)FFh%m<}a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /^nIOAeE
} OR~ui[w
S5 q1Mn
lRg?||1ik
Utility.log("Thread " + nThreadID + " is over!"); eZT8gKbjJ)
bDownOver = true; jmr .gW
//nPos = fileAccessI.write (b,0,nRead); .UL2(0
} >iOf3I-ATt
catch(Exception e){e.printStackTrace ();} z6E =%-`
} A3_p*n@
} s~ 8g
<F0^+Pf/
EA6l11{Gk1
//打印回应的头信息 o$.#A]Flb
public void logResponseHead(HttpURLConnection con) >{Hg+/
{ ")uKDq
for(int i=1;;i++) 9!Mh(KtQ
{ (=7"zECq#
String header=con.getHeaderFieldKey(i); j%nN*ms
if(header!=null) f- 9t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xWzybuLp
Utility.log(header+" : "+con.getHeaderField(header)); m- <y|3
else a&b/C*R_
break; NLL"~
} r]p3DQ
} 8N'hG,
{ac$4#Bp[B
<>\|hno}
public void splitterStop() `Fr ,,Q81\
{ -GPBX?
bStop = true; a&8K5Z%0
} >tcEx(
;Y*K!iFWH
3qe`#j
} ^w1+b;)
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d[3me{Rs
/* ,jg #^47I
**FileAccess.java nA,=g'7S
*//文件访问(定位，写) SQcic]Ep
package NetFox; "73y}'
import java.io.*; C+s/KA%
X#$ oV#
KUZi3\p9W>
public class FileAccessI implements Serializable{ 0@"'SKq
'xqyG XI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Zwc&4:5%
RandomAccessFile oSavedFile; ?Xypn#OPt
long nPos; GE!nf6>Km
o-RZwufZ`
[y`Gp#
public FileAccessI() throws IOException |cY HH$
{ %;:![?M
this("",0); .2JZ7
} }NC$Ce
ESV./~K
n?r8ZDJ'
public FileAccessI(String sName,long nPos) throws IOException (v/L
{ ,Lp"Ia
oSavedFile = new RandomAccessFile(sName,"rw"); }VJ>}i*
this.nPos = nPos; ,g7O
oSavedFile.seek(nPos); hTLf$_|P
} tB>!1}v
z]8Mv(eL
s|<n7 =J
public synchronized int write(byte[] b,int nStart,int nLen) Q;3`T7
{ )m7%cyfC
int n = -1; x!GDS>
try{ g3kbsi7_:
oSavedFile.write(b,nStart,nLen); Gpxp8[ {
n = nLen; Q"FN"uQ}x
} IwnDG;+Ap
catch(IOException e) #VX]trh,
{ }XBF#BN
e.printStackTrace (); Qt4mg?X/
} qWr=Oiu
_)5E=
45.ks.
return n; )b1hF
} QHO n?e
cN&Ebn
-rcEG!
} q&@s/k
SzpUCr"
&{8:XJe*,%
/* m=9b/Nr4
**SiteInfoBean.java A` _dj}UF
*/ NHyUHFY
package NetFox; Gn 9oInY1
eWv:wNouk
QoxYzln
public class SiteInfoBean { Wd;t(5Xl
'hr_g* i
apm%\dN
private String sSiteURL; //Site's URL +C!GV.q[
private String sFilePath; //Saved File's Path QYo04`Rl
private String sFileName; //Saved File's Name WZ?>F
private int nSplitter; //Count of Splited Downloading File }TMO>eB'
N@PwC(
p}pRf@(`\
public SiteInfoBean() .S,E=
{//nSplitter的缺省值为5 ,4"N7_!7
//default value of nSplitter is 5 ^?Xs!kJP
this("","","",5); e+BZoK ^
} ZOPK
I=&i &6v8G
H3$py|}lL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A!!!7tj
{ :|V650/
sSiteURL= sURL; ?QffSSj[s
sFilePath = sPath; b(N\R_IQ~
sFileName = sName; Wx-0Ip'9
this.nSplitter = nSpiltter; hGD@v{/
*bp09XG
*D%w r'!>
} BmpAH}%T
e]1'D
o7E|wS
public String getSSiteURL() P,pC Z+H
{ #:BkDidt2v
return sSiteURL; (Nc~l ^a
} Vc5>I_
^*fD
}d;2[fR)
public void setSSiteURL(String value) \ejHM}w3,
{ tm5{h{AM
sSiteURL = value; T=YVG@fm?
} '9u?lA^9$
jA9uB.I,"b
L<=Dl
public String getSFilePath() E'4Psx9: =
{ DQK?y=vf
return sFilePath; [(Z(8{3i
} ^=^\=9" b
q n-f&R
e bpt/q[
public void setSFilePath(String value) oQ-m
{ "[7-1}l
sFilePath = value; mmJnE
} %2dzx[s
RdD>&D$I
`,SL\\%u
public String getSFileName() ,*W~M&n"m
{ ,&@GxiU
return sFileName; ?l%4 P5
} |Io:D:
U)f('zD
bu6Sp3g
public void setSFileName(String value) A{;"e^a-^l
{ jC[_uG
sFileName = value; Q(-&}cY
} 8>WA5:]v
5QK%BiDlr
&ox
public int getNSplitter() +pG+ xI
{ t[+bZUS$~
return nSplitter; "9'3mmZm=?
} N{bg-%s10i
db,?b>,EE
8<}=f4vUj5
public void setNSplitter(int nCount) AJ6l#j-
{ Kw"e4 a
nSplitter = nCount; rzHBop-8
} N9|J\;fzT
} .?s jr4
o@gceZuk
#pPOQv:~
/* (bv{17K
**Utility.java :@jctH~
*/ %ZD]qaU0
package NetFox; P\K#q%8
DgcS@N
'V^M+ng
public class Utility { tf7HhOCYX
Gn4b*Y&M]3
(N&i4O-I
public Utility() py7Zh%k
{ !HU$V9C
YK{J"Kof
'cc8xC
} $"NH{%95}
hfI=9x/
//线程睡眠 x&DqTX?b,
public static void sleep(int nSecond) 6bUP]^d
{ 0,~s0]h0V
try{ sAU%:W{
Thread.sleep(nSecond); &'i_A%V
} [- 92]
catch(Exception e) 3.#L
{ w;}5B~).
e.printStackTrace (); Nb:j]U
} AJ>E\DK0]
} n\D/WLvM
`XE>Td>Bs
//日志 \Y"S4<"R
public static void log(String sMsg) 0cKsGDm
{ 2;T?ry7
System.err.println(sMsg); WqefH{PB
} Uf+y$n-
TYD( 6N
!m:WoQ/
public static void log(int sMsg) ;"IWm<]h;-
{ Uv[a ~'
System.err.println(sMsg); Hy:x.'i
} $+J39%Y!^
} /9kxDbj
XdThl
7#+Ih-&EQ
/* ]tu OWR
**TestMethod.java M887 Q'HSi
*/ k-3;3Mq
package NetFox; aNKw.S>
5@1h^wv
*JX$5bZsI
public class TestMethod { &Qda|
NLpKh1g
SaGI4O_\s
public TestMethod() tH;9"z# ~
{ ///xx/weblogic60b2_win.exe %8I^&~E1
try{ l-W)?d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pSC{0Y$g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A4(L47^
SiteFileFetch fileFetch = new SiteFileFetch(bean); XM!oN^
fileFetch.start(); "Cxj_V@\
} 16eP7s
catch(Exception e){e.printStackTrace ();} )|v du
t)8crX}P
j%3$ytf|p
} Tx&H1
S+KKGi_e
*0,*F~n
public static void main(String[] args) "k+ :!D
{ :T$}@& -
new TestMethod(); X~m57bj
} :CM-I_6
} 9$v\D3<Z
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