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)); wW@e#:
} )N&SrzqTK
for(int i=0;i<nEndPos.length-1;i++) oQ<[`.s
{ FN-/~Su~J
nEndPos = nStartPos[i+1]; MO8}i?u=z
} FOsd{Fw
nEndPos[nEndPos.length-1] = nFileLength; #dWz,e3
} Lj<TzPzg*
} P_1WJ
M?eP1v:<+G
e$Ds2%SaT
//启动子线程 G+8)a$?v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E+@Q u "W
for(int i=0;i<nStartPos.length;i++) {Ya$Q#l
{ Uz^N6q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (BVqmi{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C e-ru)
nStartPos,nEndPos,i); &-yRa45?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K {' atc
fileSplitterFetch.start(); 6DHK&<=D8
} +?{"Q#.>;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mrP48#Y+l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yS W$zA,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZL6HD n!
nEndPos = " + nFileLength); cmG27\cRO
// fileSplitterFetch[nPos.length-1].start(); j#5a&Z
)/$J$'mcxd
sm/aL^4
//等待子线程结束 ?% 24M\
//int count = 0; .*-8rOcc
//是否结束while循环 !Ld5Y$
boolean breakWhile = false; u /F!8#
u?Ffqt9'
?s^qWA
while(!bStop) #Q8_:dPY
{ f1 x&Fk
write_nPos(); %Rc#/y
Utility.sleep(500); JY,$B-l
breakWhile = true; Zd[rn:9\
Ek)drt7cy
\Ggh 95y
for(int i=0;i<nStartPos.length;i++) OTXZdAv
{ 5~[7|Y
if(!fileSplitterFetch.bDownOver) _nMd
{ 9Y:I)^ek
breakWhile = false; 3x+lf4"
break; 0Qt!w(
} E)_n?>Ar
} bw P=f.
if(breakWhile) ,>a!CnK=
break; j&d5tgLB
,_e[P
1Toiqb/
//count++; P8z%*/ 3NF
//if(count>4) ,eyh%k*hz
// siteStop(); 8_('[89m
} O k`}\NZL
yJ $6vmQ
^^N|:80
System.err.println("文件下载结束！"); Jl~ *@0(
} VHD+NY/
catch(Exception e){e.printStackTrace ();} WywS1viD
} Dp([r
*:n~j9V-
{rKC4:
//获得文件长度 x6UXd~ L e
public long getFileSize() SOOVUMj
{ z\]Z/Bz:6
int nFileLength = -1; NU=ru/
try{ r].n=455[
URL url = new URL(siteInfoBean.getSSiteURL()); ~7PD/dre
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :V'99Esv`
httpConnection.setRequestProperty("User-Agent","NetFox"); "v1{
5kiW@{m
0caZ_-zU
int responseCode=httpConnection.getResponseCode(); 1rm\u%
if(responseCode>=400) &b} \).5E
{ uHgq"e
processErrorCode(responseCode); LiG$M{0
return -2; //-2 represent access is error &i5@4,p y9
} vjS`;^9
d_!Z /M,
3`^@ymY
String sHeader; !Km[Qw k-
eYUb>M)
V]zc-gYI
for(int i=1;;i++) dCd~]CI
{ <\&9Odqc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ukiWNF/
//Utility.log(in.readLine()); aK_5@8+ZD
sHeader=httpConnection.getHeaderFieldKey(i); EF`}*7)
if(sHeader!=null) u} ot-!}Q
{ 0g?)j-
if(sHeader.equals("Content-Length")) :$k*y%Z*N&
{ <s9{o uZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N:lfKI
break; {kpF etXt?
} ]fM|cN8(zM
} ;{ifLI0#
else m;@q('O
break; :PO./IBX
} AF'<
} %(YQ)=w
catch(IOException e){e.printStackTrace ();} v;]rFc#Px[
catch(Exception e){e.printStackTrace ();} $mQ0w~:@
T8^9*]:@c!
f^F;`;z
Utility.log(nFileLength); *Al@|5
>d + }$dB
X)b$CG
return nFileLength; P[3i!"O>
} 25SWIpgG
eAy,T<#
S/]\GG{
//保存下载信息（文件指针位置） )~U1sW&t
private void write_nPos() 2v{WX
{ =QqH`.3
try{ &A0OYV3i.
output = new DataOutputStream(new FileOutputStream(tmpFile)); z<%P"
output.writeInt(nStartPos.length); Nr4}x7
for(int i=0;i<nStartPos.length;i++) #V>R#Oh}
{ %f]#P8VP
// output.writeLong(nPos); y[_k/.1
output.writeLong(fileSplitterFetch.nStartPos); _uIS[%4g
output.writeLong(fileSplitterFetch.nEndPos); FZi@h
} Sm'Tz&!
output.close(); h(|T.
} Z [!"x&H]h
catch(IOException e){e.printStackTrace ();} Hyb(.hlZh
catch(Exception e){e.printStackTrace ();} 2K}49*
} 4XpWDfa.}
BSm"]!D8*
,L<JG
//读取保存的下载信息（文件指针位置） ]+D@E2E
private void read_nPos() rB[J*5v
{ #mQ@4k9i
try{ $+4DpqJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :;{M0
int nCount = input.readInt(); Btm,'kBG
nStartPos = new long[nCount]; 6v)TCj/
nEndPos = new long[nCount]; SQN?[v
for(int i=0;i<nStartPos.length;i++) N5?bflY
{ ^k6_j\5j
nStartPos = input.readLong(); :v^/k]S
nEndPos = input.readLong(); D3o,2E(o
} !5ps,+o
input.close(); Os9SfL
} /QXUD.( 8
catch(IOException e){e.printStackTrace ();} 3xyrWl
catch(Exception e){e.printStackTrace ();} z CLaHx!
} t`o"K
pD{OB
Q#g`D,:o%~
private void processErrorCode(int nErrorCode) j`_S%E%X
{ @A,8>0+
System.err.println("Error Code : " + nErrorCode); +CSpL2@
} o~LJ+m6-)
CS[]T9|_
{++EX2
//停止文件下载 NUsxMhP
public void siteStop() ;.}L#'0j
{ '@{:FrG*U
bStop = true; io#}z4"'qY
for(int i=0;i<nStartPos.length;i++) KIF9[/P
fileSplitterFetch.splitterStop(); x9l7|G/$
| eBwcC#^
`J.,dqGb
} u^2`$W
} alb3oipOB
//负责部分文件的抓取 [> HKRVy
**FileSplitterFetch.java [mtp-4*
*/ ob7'''i
package NetFox; gVG^R02#<k
-`L`kL<
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import java.io.*; *)K 5<}V
import java.net.*; Sz0PZtJ
b<W\#3~G
JQQyl:=
public class FileSplitterFetch extends Thread { F.vRs|fk
!JCs'?A
7By7F:[b
String sURL; //File URL ^Om}9rXw1
long nStartPos; //File Snippet Start Position L( 6b2{"
long nEndPos; //File Snippet End Position !f~a3 {;j
int nThreadID; //Thread's ID )qxt<
boolean bDownOver = false; //Downing is over _U~R
boolean bStop = false; //Stop identical (5$Ge$
FileAccessI fileAccessI = null; //File Access interface Z ]A |"6<
K=f4<tP_
Clf$EX;~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b**vUt\
{ iK}p#"si
this.sURL = sURL; KsULQJ#,
this.nStartPos = nStart; c9/w{}F
this.nEndPos = nEnd; JH?ohA
nThreadID = id; ,3:f4e\<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SdH=1zBc
} s$fM,l:!
/H'- }C
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public void run() k3Yu"GY^
{ do" m=y
while(nStartPos < nEndPos && !bStop) vj?{={Y
{ 7 A0?tG
jF6_yw
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try{ 971=OEyq*
URL url = new URL(sURL); \,;glY=M!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n.+*_c8k
httpConnection.setRequestProperty("User-Agent","NetFox"); OX"Na2-el
String sProperty = "bytes="+nStartPos+"-"; /d&m#%9Up]
httpConnection.setRequestProperty("RANGE",sProperty); x1:mT[[$
Utility.log(sProperty); P-X|qVNK1Z
I9kz)Q o
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InputStream input = httpConnection.getInputStream(); *R6lK&
//logResponseHead(httpConnection); I_1?J* b4k
Y}[<KK}_
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byte[] b = new byte[1024]; \Z5Wp5az},
int nRead; wUvE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jIKg* @
{ S?v/diK ]J
nStartPos += fileAccessI.write(b,0,nRead); )G48,. "
//if(nThreadID == 1) <)d%c%f'`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "~Fg-{jM%
} INndTF
#Y= A#Yz,{
S.MRL,
Utility.log("Thread " + nThreadID + " is over!"); j~'.XD={
bDownOver = true; Hzz{wY
//nPos = fileAccessI.write (b,0,nRead); "ku[b\W
} a?gF;AYk
catch(Exception e){e.printStackTrace ();} ~gX1n9_n
} uyX %&r
} ?8 }pZ_j
aR2N,<Cp5
x}2nn)fdZ
//打印回应的头信息 SkDr4kds
public void logResponseHead(HttpURLConnection con) @!iS`u
{ [#KY.n
for(int i=1;;i++) Jxl'!8t
{ WsbVO|C
String header=con.getHeaderFieldKey(i); u(zgKoF9A
if(header!=null) <0';2yP"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nf pO
Utility.log(header+" : "+con.getHeaderField(header)); ,!> ~izB
else 4Uny.C]
break; Yo%U{/e
} t'K+)OK
} ;"D}"nL
d- ZUuw
+"84.PZ
public void splitterStop() 45biy(qa
{ @,<jPR.
bStop = true; /3)\^Pof
} FH}?QebSR
.]>Tj^1
7#JnQ| ]
} }8^qb5+!3
]j0+4w
{^oohW -
/* "e-z2G@z
**FileAccess.java knO X5UnS
*//文件访问(定位，写) gb,ZN^3<-
package NetFox; 10Eun }
import java.io.*; XU7to]'K
wai3g-`
Wl3S]4A
public class FileAccessI implements Serializable{ ^S|qGu,G
\zU<o~gs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xR-;,=J
RandomAccessFile oSavedFile; {)Wf[2zJ
long nPos; ?Nt(sZ-
;[o:VuTs
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public FileAccessI() throws IOException IWYQ67Yj
{ k*_Gg
this("",0); [xGwqa03
} gI7*zR4D
o;c"-^>
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public FileAccessI(String sName,long nPos) throws IOException ,LZA\XC
{ W(s5mX,Kv
oSavedFile = new RandomAccessFile(sName,"rw"); @Yt394gA%\
this.nPos = nPos; I{w(`[Nxw*
oSavedFile.seek(nPos); zgFL/a<
} oY~q^Y
]6(%tU
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public synchronized int write(byte[] b,int nStart,int nLen) & *tL)qKDc
{ ,~7~ S"
int n = -1; = V')}f~C
try{ '-myOM7
oSavedFile.write(b,nStart,nLen); 6}Y==GPt
n = nLen; [!U%''
} H%vgPQ8
catch(IOException e) 6,4vs+(|\
{ Wpf~Ji6||
e.printStackTrace (); a6zWg7 PN
} RQ0^ 1 R
,i6U*
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return n; @@@}FV&
} !{,2uQXe
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?9xWTVa8
} Z>UM gu3c
;8=Bee4
<LZ#A@]71
/* "~ =O`5V
**SiteInfoBean.java S?Cd,WxT
*/ m>Z3p7!N}
package NetFox; O-.G("
)09ltr0@"
?h1g$SBxk
public class SiteInfoBean { w3i74C&0
h>>~Bi
-5v{p
private String sSiteURL; //Site's URL @u$NB3
private String sFilePath; //Saved File's Path R{[v#sF >#
private String sFileName; //Saved File's Name "KF]s.
private int nSplitter; //Count of Splited Downloading File !pj&h0CR
BNk>D|D;
S['rTuk
public SiteInfoBean() aAP86MHO
{//nSplitter的缺省值为5 s5v}S'uO{
//default value of nSplitter is 5 E<D^j^T
this("","","",5); N[-$*F,:_
} uo?R;fX26
,2U
KtJc9dnX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6W:]'L4!
{ tSni[,4Kq
sSiteURL= sURL; -+i7T^@|
sFilePath = sPath; mb`h
sFileName = sName; >;"%Db
this.nSplitter = nSpiltter; PDH|=meXM
E3{kH 7_'\
hKhad8
} 6J- /%
>B``+Z^2
mYfHBW:
public String getSSiteURL() yD$d^/:
{ Z6M qcAJ3j
return sSiteURL; 3xRn
} T+gH38!e
i"+TKo-
j"Ew)6j
public void setSSiteURL(String value) n@H;*nI|
{ )x?)v#k
sSiteURL = value; h'GOO(
} w87$p821
~-G_c=E?
FWp ?l
public String getSFilePath() [5!{>L`
{ ml)\RL
return sFilePath; M<=e~';H
} gw">xt5
s`G}MU
;*+H&
public void setSFilePath(String value) <Mj{pN3
{ -glGOTk
sFilePath = value; 'n"we# [
} ] X)~D!mA
B7Zi|-F
-s)h ?D
public String getSFileName() ePR9r}
{ A42!%>PB
return sFileName; 8N |K
} )lz)h*%#
?|Z~mE
~e)"!r
public void setSFileName(String value) b>#=7;
{ 6f t6;*,
sFileName = value; 4MzPm~Ct
} 2 p}I
0`v-pL0|
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public int getNSplitter() UUvCi+W
{ &sYxe:H
return nSplitter; KLuOg$i
} %<p/s;eu
^wwS`vPb
R>5Xv%R
public void setNSplitter(int nCount) K3WaBcm
{ >lyE@S sA
nSplitter = nCount; z;/8R7L&
} Bva2f:)K|
} D#`>p
D dCcsYm,
4b,+;
/* !g)rp`?
**Utility.java ^ uwth
*/ u]`0QxvZ
package NetFox; \~Ml<3Zd:
a({N}ZDo
$b7@S`5
public class Utility { \D]9:BNJ
Lp4F1H2t-
zuFPG{^\#
public Utility() 9`"#OQPn1
{ jT F"
0jPUDkH*
:>_oOn[_
} M"qS#*{
$A/?evJi8R
//线程睡眠 4gVIuF*pS
public static void sleep(int nSecond) X8R:9q_
{ SkCux
try{ 28c6~*Te#
Thread.sleep(nSecond); JR&yaOws
} s aHY9{)
catch(Exception e) .Y8P6_
{ ?Pf#~U_
e.printStackTrace (); 0L,!o[L*
} `CBXz!v!O
} ukc 7Z OQ
Q00v(6V46
//日志 NpKyrXDJv
public static void log(String sMsg) l%?4L/J)#
{ loE;q}^
System.err.println(sMsg); Z5*(xony0
} .c@Y?..+
fOdqr
n6M#Xc'JA
public static void log(int sMsg) F+ RE
{ =K|#5p`
System.err.println(sMsg); i3d2+N`
} s1#A0%gx
} ue@W@pj
HD2C^V2@M
]>*VEe}hJ
/* ;volBfv
**TestMethod.java /0fHkj/J=B
*/ o~L(;A]yN
package NetFox; "M\rO!f:
XZ3fWcw[
W\5 -Yg(@
public class TestMethod { 4~ L1~Gk
Q>9bKP
so/0f1R?~
public TestMethod() A"s?;hv\fS
{ ///xx/weblogic60b2_win.exe bAN>\zG+
try{ XzqB=iX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HY?#r]Ryt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~-uf%=
SiteFileFetch fileFetch = new SiteFileFetch(bean); gy~2LY!}
fileFetch.start(); ^8]7
} (NDC9Lls
catch(Exception e){e.printStackTrace ();} ;*9<lUvu
LHu
@p}_"BHYWt
} 1[#sHj$Na`
$<C",&
*//z$la
public static void main(String[] args) 6gO( 8
{ 5K682+^5
new TestMethod(); Bt5 P][<
} n9k
} ,O:p`"3`0=
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