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)); 20SF<V
} D@/9+]-,
for(int i=0;i<nEndPos.length-1;i++) E 6>1Fm8%V
{ LH?gJ8`
nEndPos = nStartPos[i+1]; oT9XJwqnv
} MY0[Oq cm=
nEndPos[nEndPos.length-1] = nFileLength; +oxqS&$L
} FvtM~[Q
} z9OMC$,V
K-g=td/@
=CD:.FG.
//启动子线程 A;/Xt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fzPgX
for(int i=0;i<nStartPos.length;i++) K284R=j -&
{ H4K(SGx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m\R@.jkZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (o6A?37i
nStartPos,nEndPos,i); _BeX7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gn;nS{A
fileSplitterFetch.start(); f"}0j|Gg
} ;I0yQlx|U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a8lo!e9q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]ci|$@V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0*]<RM
nEndPos = " + nFileLength); <9MQ
// fileSplitterFetch[nPos.length-1].start(); n]6w)wE(
gvwCoCbb
9e :d2
//等待子线程结束 MO(5-R`
//int count = 0; ;1(qGy4
//是否结束while循环 D%5 {A=
boolean breakWhile = false; YA/H;707l
W+-f `
mtHi9).,y|
while(!bStop) 0zq\ j
{ =:0IHyB#0
write_nPos(); ej??j<]
Utility.sleep(500); G%W03c
breakWhile = true; CO6XIgTe
zL[U;
@N:3`[oB
for(int i=0;i<nStartPos.length;i++) m8j#{[NE
{ :jN;l
if(!fileSplitterFetch.bDownOver) G41$oalQ1
{ G1n>@Y'j''
breakWhile = false; g'l7Jr3
break; Q%b46"
} .bY1N5=sz
} +MZ2e^\F
if(breakWhile) `zvT5=*-#
break; u.xA}yVS
U%SNROj
O.m.]%URW
//count++; k%bTs+]*
//if(count>4) (HP={MrV
// siteStop(); Ug[F3J|Mu
} p_kTLNZd9
9BgQoK@
rqG6Ll`=+
System.err.println("文件下载结束！"); EzY scX.[
} fh5^Gd~
catch(Exception e){e.printStackTrace ();} s*A|9uf5
} jak|LOp
h^3Vd K,
E`Zh\u)
//获得文件长度 5E!|on
public long getFileSize() a6K$omu
{ &`9bGO
int nFileLength = -1; C J}4V!;|
try{ 9ixnf=$Jp
URL url = new URL(siteInfoBean.getSSiteURL()); G#=b6DB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S3[oA&
httpConnection.setRequestProperty("User-Agent","NetFox"); L:];[xa%
hF?\K^tF
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int responseCode=httpConnection.getResponseCode(); ZBh@%A
if(responseCode>=400) 'XjHB!!hU
{ J1wGK|F~
processErrorCode(responseCode); %>QSeX
return -2; //-2 represent access is error e[Ul"pMvS`
} l=.InSuLT
DyV[+P
(j\UoKLRt
String sHeader; bgx5{!A
_M[[o5{
(>/Dw|,m
for(int i=1;;i++) r;s3(@[,@
{ ~o\]K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WW Kr & )
//Utility.log(in.readLine()); "Mu$3w
sHeader=httpConnection.getHeaderFieldKey(i); .cnw?EI
if(sHeader!=null) jq]\oY8y
{ ]{l O
if(sHeader.equals("Content-Length")) ;Q%19f3,6
{ ckkM)|kK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pRfHbPV?
break; Wn)A/Z ^r
} .m % x-i
} N_~Wu
else v,O&UrZ
break; 4iB)oR
} 3_['[}
} a>e 1jM[
catch(IOException e){e.printStackTrace ();} 2LK*Cv[
catch(Exception e){e.printStackTrace ();} jZgnt{
DL/*t.)"et
W!Os ci
Utility.log(nFileLength); kO O~%|1CP
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N,'qMoNf
return nFileLength; GVPEene
} 7*W$GCd8
5EZr"[8M
Pxuz {
//保存下载信息（文件指针位置） pPqbD}p
private void write_nPos() hB1iSm
{ A-NC,3
try{ \y+F!;IxL
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~<Qxw>S#
output.writeInt(nStartPos.length); EwJn1Mvq
for(int i=0;i<nStartPos.length;i++) qQ\hUii
{ }z%/6`7)|
// output.writeLong(nPos); CMB$RLf
output.writeLong(fileSplitterFetch.nStartPos); hQrsZv:Q
output.writeLong(fileSplitterFetch.nEndPos); 6j.(l4}
} MkIO0&0O
output.close(); 2H0q\zZ
} "VhrsVT
catch(IOException e){e.printStackTrace ();} 9n2%7dLQ*
catch(Exception e){e.printStackTrace ();} %.}
} Z)>a6s$ih<
q+=@kXs>+
#SOj4W
//读取保存的下载信息（文件指针位置） bSKV|z/x
private void read_nPos() M;@03 x W
{ ^C#bW<T
try{ *fyEw\`a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dEl3?~
int nCount = input.readInt(); )HiTYV)]'
nStartPos = new long[nCount]; nWg)zj:
nEndPos = new long[nCount]; GeR-k9
for(int i=0;i<nStartPos.length;i++) 9!<3qx/
{ :'Kx?Es
nStartPos = input.readLong(); mr\L q~*c
nEndPos = input.readLong(); F973U
} <qZ+U4@I)
input.close(); "U~@o4u;
} <{~UKi
catch(IOException e){e.printStackTrace ();} ;&:Et
catch(Exception e){e.printStackTrace ();} 246!\zf
} mLdyt-1
hndRgCo
k:yu2dQh
private void processErrorCode(int nErrorCode) S~`AnX3!
{ mAERZ<I
System.err.println("Error Code : " + nErrorCode); T[II;[EiE
} :9< r(22
<JuJ`t
Tm,L?Jh
//停止文件下载 Q>Q}/{8!
public void siteStop() "uNxKLDB
{ i2c<q0u
bStop = true; 8?R_O}U
for(int i=0;i<nStartPos.length;i++) V&nJT~k
fileSplitterFetch.splitterStop(); HBYpjxh
ho=]'MS|
{:j!@w3
} d|HM
} \d`Sz *
//负责部分文件的抓取 ,3[<C)'[
**FileSplitterFetch.java X+BSneu
*/ y6yseR!
package NetFox; $+N^ s^
Lu5.$b
1F8EL)9
import java.io.*; j ZafwBi
import java.net.*; 7l EwQ
YA8~O5
=&xoyF
public class FileSplitterFetch extends Thread { <08V-
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<;"=ah7A
String sURL; //File URL cC]1D*Bn
long nStartPos; //File Snippet Start Position LxDhthZi_
long nEndPos; //File Snippet End Position %P6!vx:&^b
int nThreadID; //Thread's ID N*-Z Jv
boolean bDownOver = false; //Downing is over _ h-X-s Y
boolean bStop = false; //Stop identical HK.J/Zr
FileAccessI fileAccessI = null; //File Access interface H!=BjU1Pmg
jg/<"/E
.k(_j.v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException md s\~l73
{ !d)i6W?
this.sURL = sURL; ?5gpk1
this.nStartPos = nStart; q,Q|Uvpk
this.nEndPos = nEnd; h}_q
nThreadID = id; {<n)zLy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m@?e <$
} Z}f_\d'
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e8v=n@0
public void run() SW,Po>Y
{ a^,RbV/
while(nStartPos < nEndPos && !bStop) M*uG`Eo&
{ hgltD8,
Puh&F< B
?Ea"%z*c5
try{ rpWy 6oD
URL url = new URL(sURL); #+\G- =-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9mm(?O~'p
httpConnection.setRequestProperty("User-Agent","NetFox"); /ep~/#Ia
String sProperty = "bytes="+nStartPos+"-"; ?8/h3xV;
httpConnection.setRequestProperty("RANGE",sProperty); ]vErF=[U,
Utility.log(sProperty); ';F][x5j
1>{(dd?L
)P])0Y-
InputStream input = httpConnection.getInputStream(); {D#`+uw
//logResponseHead(httpConnection); xx8na8
(v}:
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byte[] b = new byte[1024]; kRPg^Fw"Vw
int nRead; 0rUf'S ?K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @9a=D<'>
{ mws.)
nStartPos += fileAccessI.write(b,0,nRead); A@r,A?(
//if(nThreadID == 1) G.T1rUh=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !HYqM(|{.
} cGKk2'v?
4N&}hOM'S
?CDq^)T[
Utility.log("Thread " + nThreadID + " is over!"); q4oZJ-`
bDownOver = true; ,,gYU_V
//nPos = fileAccessI.write (b,0,nRead); e+TNG &_
} N5DS-gv
catch(Exception e){e.printStackTrace ();} b.&YUg[#
} |zKcL3*
} F^-4Pyq@
jK53-tF~I
;*p}~#2
//打印回应的头信息 Q{60^vg
public void logResponseHead(HttpURLConnection con) 7j8_O@_
{ `RRORzXoS
for(int i=1;;i++) P9vROzXK
{ [G*mQ@G9
String header=con.getHeaderFieldKey(i); ;U&VPIX$
if(header!=null) Z)%p,DiNM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e`^j_VnEH
Utility.log(header+" : "+con.getHeaderField(header)); |~Iw
else AP%h!b5v
break; ";]m]PRAam
} 9`AQsZ2
} U^D7T|P$V
b8&9pLl
,fn=%tiUk
public void splitterStop() }=gGs
{ <*P1Sd.
bStop = true; O/Vue
} g,nEiL
XJ9>a-{
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} gN%R-e0
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MZ'HMYed
/* C'ZU .Y
**FileAccess.java [aC(Ga}
*//文件访问(定位，写) }- Sr@bE
package NetFox; RiklwR#~r/
import java.io.*; \N30SG?o
DNPK1e3a{
<3KrhhH
public class FileAccessI implements Serializable{ ;<\*(rUe
@Klj!2cv$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 trLs4o,
RandomAccessFile oSavedFile; N<x5:f#+
long nPos; dq2v[?*R
c1[;a>
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public FileAccessI() throws IOException 6c:$[owC
{ ?9:\1)]
this("",0); ?jbam!A
} W2RS G~|
a$ }^z
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public FileAccessI(String sName,long nPos) throws IOException Hg4Ut/0
{ @)B_e*6>'
oSavedFile = new RandomAccessFile(sName,"rw"); Z5Cv$bUc
this.nPos = nPos; W3b\LnUa
oSavedFile.seek(nPos); ~X/T6(n$
} [>E0(S]
IWkBq]Y
})B)-8
public synchronized int write(byte[] b,int nStart,int nLen) ^:BRbp37i
{ \MU4"sXw
int n = -1; PA E)3
try{ &N EzKf
oSavedFile.write(b,nStart,nLen); JsV#:
n = nLen; S<TfvQ\,"@
} 4?Io@[7A)
catch(IOException e) (&S v$L@
{ ="`y<J P
e.printStackTrace (); 0*q:p`OLw*
} UxW~yk
bWqGypq4
QO8/?^d
return n; [7bY(
} W6pS.}
jV(ISD
B~^\jRd"
} |l9AgwDg
%UmE=V
bnlL-]]9z
/* R~`Y6>o~9:
**SiteInfoBean.java gVGq
*/ QwhPN'U
package NetFox; ;BqX=X+#
E$cr3 t7Xy
+wmfl:\^{H
public class SiteInfoBean { >,DR{A2hSB
7 ir T6O<.
}5~;jN=k
private String sSiteURL; //Site's URL L2 I/h`n"
private String sFilePath; //Saved File's Path G 5)?!
private String sFileName; //Saved File's Name 6c2fqAF>i
private int nSplitter; //Count of Splited Downloading File F?UL0Q|uv
\1tce`+
nP}/#Wy
public SiteInfoBean() |aZ^K\yIF
{//nSplitter的缺省值为5 /fX]Yu
//default value of nSplitter is 5 $1axZ~8sS
this("","","",5); O @w=
} H:|yu
<a'j8pw9i
2]@U$E='s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z >pq<}R6
{ U9JqZ!
sSiteURL= sURL; m_pK'jc
sFilePath = sPath; @FQ@*XD
sFileName = sName; ;>PV]0bOm>
this.nSplitter = nSpiltter; -/h$Yb
, 7}Ri
]|-y[iu
} @gZ%>qe
Y$(G)Fs
w'UP#vT5&
public String getSSiteURL() 7|{QAv
{ }\1V;T
return sSiteURL; 4-m}W;igu
} ddw!FH2W (
"dA"N$
&oT]ycz%
public void setSSiteURL(String value) tvd/Y|bV=
{ *bR _ C"-
sSiteURL = value; FCg,p2
} W7.]V)$wM
aUd633
sUg7
public String getSFilePath() 2hquE_1S[w
{ @.%ll n
return sFilePath; W] RxRdY6[
} d@C93VYp
_mcD*V
9;:Lf
public void setSFilePath(String value) xEbcF+@
{ wt-)5f'{
sFilePath = value; U2G\GU1 X
} T'w=v-(J
oqG 0 @@
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public String getSFileName() u\6:Txqq
{ v=|ahsYC
return sFileName; IuRKj8J)o
} XrYz[h*)!
6}[W%S]8
gPDc6{/C<
public void setSFileName(String value) ;0ake%v]
{ 'GAjx{gM
sFileName = value; ,KZ_#9[>
} @*F NWT6
0'a.Ypf
{AJspLcG
public int getNSplitter() L>cTI2NB.
{ x H\5T!
return nSplitter; \vKMNk;kz
} =T9QmEBm
$LKniK
mhh8<BI
public void setNSplitter(int nCount) 92XzbbLp
{ uQrD}%GI
nSplitter = nCount; P.LMu
} nd-y`@z
} %|4Nmf$:Og
`NrxoU=
]Rz]"JZ\S
/* $dq R]'
**Utility.java e3&R3{
*/ Rs7=v2>I
package NetFox; &d=j_9
YMC*<wXN
|]^OX$d
public class Utility { F?TAyD*
5_{C \S`T
@99@do|C
public Utility() 1)H+iN|im/
{ {i3]3V"Xp
`5Q0U%`W
/z`LB
} zuXJf+]
UP^{'eh
//线程睡眠 }~yhkt5K
public static void sleep(int nSecond) _z~|*7@
{ Kh}#At^C8e
try{ ,SH))%Cyt
Thread.sleep(nSecond); c:M~!CXO
} (m25ZhW
catch(Exception e) d_]zX;_
{ b<NI6z8\
e.printStackTrace (); 3`$-
} g7rn|<6FI
} DhYQ>Gv8U
`VwZDU~6
//日志 i_Ab0vye
public static void log(String sMsg) w>J|416
{ ):31!IC
System.err.println(sMsg); b+9M? k"
} )u`q41!
FTsvPLIv"
EE=!Y NP]
public static void log(int sMsg) JT#jJ/^
{ {rBS52,Z#
System.err.println(sMsg); p~6/
} { owK~
} fKb8)PDP
Z`Rrv$M!
Nyip]VwMJ
/* uPQ:}zL2
**TestMethod.java ^giseWR(
*/ '1_CMr
package NetFox; $OldHe[p
gDa}8!+i
=`Pgo5A
public class TestMethod { sEm-Td+A5
mfc\w'
pa*bqPi
public TestMethod() 3dTz$s/[
{ ///xx/weblogic60b2_win.exe 8m\*~IX=
try{ gi#bU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9@/X;zO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6w|s1!Bl
SiteFileFetch fileFetch = new SiteFileFetch(bean); >|'u:`A
fileFetch.start(); W_8N?coM
} w3WBgH
catch(Exception e){e.printStackTrace ();} slaYr`u
Z9,-FO{#3-
F[RQ6PW
} Nk*d=vj
$aDAD4mmm
\R\?`8Orz
public static void main(String[] args) p#go<Y#
{ Q'>pOtJG*J
new TestMethod(); )O*\}6:S
} 3|x*lmit
} :[YHJaK
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