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)); u>Kvub
} "k@/Z7=
for(int i=0;i<nEndPos.length-1;i++) JA2}
{ ^bw~$*"j#
nEndPos = nStartPos[i+1]; w%u[~T7OI
} Sgk{NM7|k
nEndPos[nEndPos.length-1] = nFileLength; %R5MAs&-5
} -]MP,P%
} tm#y`1-
JS.'v7
0-O.*Q^
//启动子线程 2xxwQwg8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \O4=mJ
for(int i=0;i<nStartPos.length;i++) n;Wf|>
{ {oC69n:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K#yH\fn8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R')GQ.yYq
nStartPos,nEndPos,i); +*~3"ww<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 87*[o
fileSplitterFetch.start(); `Wt~6D e
} Z ' 96d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J(*"S!q)6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s'w0pZqj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7oSuLo=
nEndPos = " + nFileLength); ?2/M W27w
// fileSplitterFetch[nPos.length-1].start(); Bd[}A9O[
`Hu;Gdj=
M|u5Vs1
//等待子线程结束 ?5M2DLh~
//int count = 0; `-\JjMSQ1
//是否结束while循环 \Vq;j 1
boolean breakWhile = false; `215Llzk;
he6) L6T
Ct33S+y
while(!bStop) j;vaNg|vQ
{ 5~5ypQj
write_nPos(); I[Y?f8gJ
Utility.sleep(500); t;6/bT-
breakWhile = true; >b${rgCvQ
tq93 2M4
M_uij$1-
for(int i=0;i<nStartPos.length;i++) #&gy@!a~
{ t:n|0G(
if(!fileSplitterFetch.bDownOver) OOwJ3I >]>
{ q+Q)IVaU81
breakWhile = false; ,g.=vQm:?
break; Q:=/d$*xd
} k9?+9bExXA
} 40ZB;j$l
if(breakWhile) c *noH[
break; arrcHf4O
o%7yhCY
?2Dz1#%D
//count++; Kj5f:{Ur
//if(count>4) *a@UV%u
// siteStop(); )9,"~P2[R
} 9_$Odc%]
`Nr7N#g+u
Qgi:q
System.err.println("文件下载结束！"); "+_0idpF
} tx-bzLo\
catch(Exception e){e.printStackTrace ();} osI(g'Xb
} )2hoO_l:
m#p^'}]!;
D.f=!rT7E7
//获得文件长度 wxrT(x|
public long getFileSize() Reo0ZU>
{ wtyu"=
int nFileLength = -1; e2F7G>q:5
try{ sP!qv"u
URL url = new URL(siteInfoBean.getSSiteURL()); @x4Dt&:"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E$ rSrT(
httpConnection.setRequestProperty("User-Agent","NetFox"); W,+91rup
Q0q$ZK6C
0:p#%Nvg
int responseCode=httpConnection.getResponseCode(); n!nv.-n
if(responseCode>=400) } U.B$4Q
{ L1BpY-=
processErrorCode(responseCode); 'z:p8"h}
return -2; //-2 represent access is error b.+\qaR
} .(ir2g
ya=51~ by"
I'hQbLlG
String sHeader; `$HO`d@0*R
%cL:*D4oz
TMBdneS-s
for(int i=1;;i++) /0(KKZ)
{ RB!E>]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L&%iY7sC`
//Utility.log(in.readLine()); HVpaVM
sHeader=httpConnection.getHeaderFieldKey(i); 6h%(0=^
if(sHeader!=null) N0f}q1S<-A
{ \8ZNXCP
if(sHeader.equals("Content-Length")) &9>d
{ m`cG&Ar5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <}%*4mv
break; DSp@
} cCIEG e6
} mLO6`]p{H
else tK*f8X+q
break; ^=j$~*(LmX
} lVHJ}(<'p
} WP9=@X Z
catch(IOException e){e.printStackTrace ();} :C5N(x
catch(Exception e){e.printStackTrace ();} 7_,X9^z
crQuoOl7
eNX-2S
Utility.log(nFileLength); 5l#)tX.by
S6 *dp68
Wu(GC]lTG
return nFileLength; tti.-
} FgxQ}VvlH
0Qz \"gr
p*Cbe\
//保存下载信息（文件指针位置） U<x3=P
private void write_nPos() 9viC3bj.o
{ "rtmDNpL
try{ 5h&8!!$[
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;A_QI>>
output.writeInt(nStartPos.length); z; +x`i.
for(int i=0;i<nStartPos.length;i++) smggr{-
{ tP9}:gu
// output.writeLong(nPos); ?a% u=G
output.writeLong(fileSplitterFetch.nStartPos); ?(z3/"g]
output.writeLong(fileSplitterFetch.nEndPos); _kSus
} lz>hP
output.close(); ej~ /sO
} #R$!|
catch(IOException e){e.printStackTrace ();} `Cc<K8s8
catch(Exception e){e.printStackTrace ();} VQyDd~Za
} uB BE!w_
G+ToZ&f@
e=U7w7(s9
//读取保存的下载信息（文件指针位置） Yi:+,-Fso
private void read_nPos() qXW5_iX
{ P;GUGG*W
try{ tF4"28"h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N.]8qzW
int nCount = input.readInt(); eL.S="
nStartPos = new long[nCount]; :3k(=^%G!
nEndPos = new long[nCount]; ][Kj^7/
for(int i=0;i<nStartPos.length;i++) M1:m"#=
{ {,m!%FDL
nStartPos = input.readLong(); L_(|5#IDw
nEndPos = input.readLong(); .3[YOM7h
} |b@-1
input.close(); KM6r}CDHs
} .._wTOSq
catch(IOException e){e.printStackTrace ();} B*{CcQ<5
catch(Exception e){e.printStackTrace ();} KQk;:1hW
} $ _zdjzT
+#O?sI#
ppxu\a
private void processErrorCode(int nErrorCode) I<$lpU_H
{ B}vI<?c
System.err.println("Error Code : " + nErrorCode); q8U]Hyp(`
} 1t6UI4U!$
X- zg
_.j KcDf
//停止文件下载 j%lW+[%
public void siteStop() B=f{`rM)~W
{ o_cj-
bStop = true; qVf~\H@
for(int i=0;i<nStartPos.length;i++) rl4-nA
fileSplitterFetch.splitterStop(); _z_uz\#,
!cfn%+0
n[<Vj1n
} {d)+a$qj
} {2,V3*NF
//负责部分文件的抓取 LWY`J0/
**FileSplitterFetch.java MSA*XDnN
*/ M/BBNT
package NetFox; O!a5
bz@4obRqf
?O.&=im_
import java.io.*; :U~[%]
import java.net.*; {pVD`#Tl[
*w!H -*`
9 eP @}C6
public class FileSplitterFetch extends Thread { +s`n]1HC
[hs{{II
rVkHo*Q
String sURL; //File URL kWWb<WRW:
long nStartPos; //File Snippet Start Position hI"I#(*jA%
long nEndPos; //File Snippet End Position s3q65%D
int nThreadID; //Thread's ID _:{XL c
boolean bDownOver = false; //Downing is over N-suBRnW
boolean bStop = false; //Stop identical q*2ljcb55
FileAccessI fileAccessI = null; //File Access interface il*bsnwpZv
9khD7v
sx6` g;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ='~C$%
{ L./UgeZ
this.sURL = sURL; MVV<&jho{^
this.nStartPos = nStart; Zcc6E2
this.nEndPos = nEnd; xX}vxhN
nThreadID = id; IKpNc+;p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 67d0JQTu
} &D/_@\ 0
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0%vXPlfnY
public void run() $"sf%{~
{ <jV_J+#
while(nStartPos < nEndPos && !bStop) KnlVZn[3t
{ /<GygRs
.Emw;+>
.t\5H<z
try{ 4%B${zP(.}
URL url = new URL(sURL); #[IQmU23
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zc(-dMlK
httpConnection.setRequestProperty("User-Agent","NetFox"); t0/fF'GZD
String sProperty = "bytes="+nStartPos+"-"; sURHj&:t|
httpConnection.setRequestProperty("RANGE",sProperty); TzVNZDQ`Jl
Utility.log(sProperty); ^G15]Pyw
* ,,D%L
2&dtOyxo>
InputStream input = httpConnection.getInputStream(); )PZ'{S
//logResponseHead(httpConnection); e KET8v[
0?k/vV4
JrO2"S
byte[] b = new byte[1024]; O GSJR`yT
int nRead; &FGz53fd4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X|X6^}
{ o: TO[
nStartPos += fileAccessI.write(b,0,nRead); nsYS0
//if(nThreadID == 1) V+_L9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dg\fjuK9
} $$AKz\
WnA]gyc
^oM*f{9
Utility.log("Thread " + nThreadID + " is over!"); +b 1lCa_
bDownOver = true; aM~M@wS
//nPos = fileAccessI.write (b,0,nRead); iz>a0~(K
} wOINcEdx
catch(Exception e){e.printStackTrace ();} haS`V
} s(F^P
} a(!:a+9WOP
A:>G:X5t
jPhOk>m
//打印回应的头信息 t[%9z6t
public void logResponseHead(HttpURLConnection con) ^KmyB6Yg
{ BT>8
for(int i=1;;i++) Z3=t"
{ qd"*Td
String header=con.getHeaderFieldKey(i); P5kkaLzG
if(header!=null) db4Ol=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LKtr>u
Utility.log(header+" : "+con.getHeaderField(header)); pz~AsF
else )N<>L/R
break; g;Bq#/w
} XswEAz0=
} (q*Za
,:j^EDCsaJ
oljl&tuQy
public void splitterStop() + ,0RrD )
{ G ?H`9*y
bStop = true; OP{ d(~+
} -&y{8<bu4H
]Ocf %(
a'rN&*P
} %.[t(F
|{<g-)
q#F;GD
/* DO(FG-R
**FileAccess.java yD$rls:v<
*//文件访问(定位，写) "3W!p+W
package NetFox; P8piXG
import java.io.*; PKty'}KF
3@_je)s
/$0@To
public class FileAccessI implements Serializable{ mq do@
tNoo3&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /EA4-#uw
RandomAccessFile oSavedFile; % =br-c
long nPos; Hi|'
%BC*h}KGH
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public FileAccessI() throws IOException ?&j[Rj0pH
{ #Q"el3P+q
this("",0); bw ' yX
} xLPyV&j-
M8Q-x-7
8S&`
public FileAccessI(String sName,long nPos) throws IOException dq[j.Nmq
{ JY~s-jxa
oSavedFile = new RandomAccessFile(sName,"rw"); /)e&4.6
this.nPos = nPos; p(:$HP)R
oSavedFile.seek(nPos); 8(\Az5%
} 1ki##v[ W8
8J7xs6@
]@)X3}"!
public synchronized int write(byte[] b,int nStart,int nLen) z ~T[%RjO
{ s-J>(|
int n = -1; Z ~:S0HDP
try{ Da0E)
oSavedFile.write(b,nStart,nLen); ej]^VS7w[r
n = nLen; !Z`~=n3bk
} :OUNZDL
catch(IOException e) W -8<sv$b
{ {;=I69X
e.printStackTrace (); uL1e?
} ]4@_KKP
1}}.e^Tsfr
#db8ur3?
return n; @q}.BcSg
} j_H{_Ug
s 'u6Ep/V
^8a,gA8.
} ck){N?y
?sfA/9"
Nc,"wA
/* 2kp.Ljt@
**SiteInfoBean.java kVCSFF*
*/ |[)t4A"}
package NetFox; =hH>]$J[
kS%FV;9>(
G29PdmY$<
public class SiteInfoBean { O$V 6QJ
pej/9{*xg(
b54<1\&
private String sSiteURL; //Site's URL ?kI-o0@O.
private String sFilePath; //Saved File's Path @TdPeTw\
private String sFileName; //Saved File's Name By]XD~gcP
private int nSplitter; //Count of Splited Downloading File kOmTji7
[-x~Q[
@kenv3[Lc
public SiteInfoBean() a]>gDDF
{//nSplitter的缺省值为5 7<<pP
//default value of nSplitter is 5 y{0`+/\`
this("","","",5); h/?8F^C#v
} rp6Y&3p.
>JkQU e
;e_dk4_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ou"QUn|
{ f<= #WV
sSiteURL= sURL; <x,u!}5J
sFilePath = sPath; F42r]k
sFileName = sName; @F]6[
this.nSplitter = nSpiltter; Cg |_) _w
Oz#$x
3;zJ\a.+
} m"t\@f
^/47*vcN5
Ek~Qp9B
public String getSSiteURL() 2asA]sY
{ 9x0B9&
return sSiteURL; (\{9W
} r /63
mT <4@RrB
YAv-5
public void setSSiteURL(String value) E{[c8l2B
{ mk2T
sSiteURL = value; #I|Vyufw
} (C={/waJ
CkE@Ll3Z
zmQ V6o=k
public String getSFilePath() UTGR{>=>
{ OkGg4X|9
return sFilePath; 8 k9(iS
} @>,3l;\Zh
{a.{x+!5I-
d8`^;T ;}d
public void setSFilePath(String value) [cwc}f^
{ Oh9wBV
sFilePath = value; B q+RFo
} `<i|K*u
6Xb\a^q
z'=*pIY5f
public String getSFileName() $~`a,[e<
{ =unMgX]$
return sFileName; M7-piRnd4
} <mjH#aSy
gQ3Co./
)tl=tH/$
public void setSFileName(String value) */sVuD^b`
{ Z#BwJHh
sFileName = value; &F1h3q)L
} 8W)3rD>
}00mJ]H(
7Te`#"
public int getNSplitter() C(Ujx=G+3
{ "(PJh\S>S
return nSplitter; s\_-` [B0
} \Si@t{`O
58,_
g6o-/A!Q3
public void setNSplitter(int nCount) *M\Qt_[
{ U>7"BpC
nSplitter = nCount; hSSF]
} 0kS[`a(}J
} M;OY+|uA
zDeh#
x tg3~/H
/* >gM|:FG
**Utility.java V|zzj[c
*/ I gcVl/d
package NetFox; IE.JIi^w
d!7cIYVZ
KT~J@];Fb
public class Utility { %Ez%pT0TQ#
O|m-Uz"+
3.U5Each-
public Utility() 6[,*2a8
{ X[_w#Hwp-
*q_ .y\D
FKY|xG9
} Yxz(g]
fp|!LU
//线程睡眠 EQ1wyKZS2g
public static void sleep(int nSecond) GQhzQM1HS
{ :A $%5;-kO
try{ |C?<!6.QmV
Thread.sleep(nSecond); <use+C2
} 6pDb5@QjTy
catch(Exception e) ZGK*]o=)
{ L3lf28W
e.printStackTrace (); G 5w:
} QE[ETv
} 6DqV1'
9Xo'U;J
//日志 g#ubxC7t<
public static void log(String sMsg) 34_:.QK-
{ 8`XpcK-0
System.err.println(sMsg); <\eHK[_*
} +RQlMAB
KArt4+31
u'M\m7
public static void log(int sMsg) pE@Q (9`b{
{ -twV?~f
System.err.println(sMsg); o#gb+[
} />c F
} Zc(uK{3W-
}eb}oK
#]<j.Fc`
/* S{gB~W
**TestMethod.java 1.U5gW/3L
*/ 0G ^73Z
package NetFox; <3zA|
<gRv7 ?V[z
(@@t,\iF
public class TestMethod { If>k~aL7I
TbbtD"b?
pYIm43r H
public TestMethod() |1C=Ow*"
{ ///xx/weblogic60b2_win.exe PrqN5ND
try{ mu`h6?v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xU+c?OLi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H!mNHY_fA
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6=A
fileFetch.start(); L;$Gn"7~
} Tl"GOpH\]
catch(Exception e){e.printStackTrace ();} - `F#MN
8$9<z
D]n9+!Ec1f
} sT:$:=
5/4N Y
k/bY>FY2r
public static void main(String[] args) DU(QQ53
{ v&6I\1
new TestMethod(); veX#K#
} gE2k]`[j]
} A (z lX_
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