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)); NVWeJ+w
} bMOM`At>z
for(int i=0;i<nEndPos.length-1;i++) |hQ|'VCN
{ HKN"$(Q
nEndPos = nStartPos[i+1]; qpqz. {\
} 7qK0!fk5
nEndPos[nEndPos.length-1] = nFileLength; 3N0X?* (x|
} E?4@C"Na
} q)xl$*g
v|2q2bz
Q4LlToHn
//启动子线程 `G0rF\[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @"Fp;Je\bN
for(int i=0;i<nStartPos.length;i++) w[oQ}5?9'
{ 3b\8907
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;s.5\YZ"k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aX'g9E
nStartPos,nEndPos,i); ;VlZd*M?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1(7.V-(G
fileSplitterFetch.start(); m?% H<4X
} BRXb<M^;_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &zX 3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); + >gbZ-S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [^}>AC*im
nEndPos = " + nFileLength); qTh='~m4[
// fileSplitterFetch[nPos.length-1].start(); Fxth>O`$
A~GtK\=;
Ld3Bi2d|
//等待子线程结束 ' raB
//int count = 0; ) UDJ[pL@
//是否结束while循环 ml33qXW:
boolean breakWhile = false; ?}3PJVy?
.4C[D{4
M?~<w)L}
while(!bStop) eMl]td rI
{ Jt>[]g$
write_nPos(); 8Z4?X%
Utility.sleep(500); %][$y7
breakWhile = true; <.=#EV^i
2~&hstd%
L_lDFF
for(int i=0;i<nStartPos.length;i++) L740s[,`o#
{ &Ky u@Tt
if(!fileSplitterFetch.bDownOver) <f.>jjwFE
{ JXLWRe
breakWhile = false; X=p3KzzX
break; Y7kb1UG
} Vy% :\p+
} 7moElh v
if(breakWhile) xjK_zO*dLq
break; 2l)9Lz=;L
5Q$r@&qp
G_^iR-
//count++; ^YG7dd_
//if(count>4) 5&?KW)6 Rz
// siteStop(); (3N"oE.b]
} .A*VLF*m
oGJ*Rn)Z
5qd_>UHp
System.err.println("文件下载结束！"); XYb^Cs;
} KZrMf77=
catch(Exception e){e.printStackTrace ();} iF [?uF
} 4z9#M;qT
c:llOHA
=CjNtD2]
//获得文件长度 &}nBenYp
public long getFileSize() YXX36
{ J+71FP`ZH
int nFileLength = -1; &SjHrOG?
try{ .|-l+
URL url = new URL(siteInfoBean.getSSiteURL()); hg?j)jl|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XVrm3aj(m
httpConnection.setRequestProperty("User-Agent","NetFox"); so!w!O@@
1tc]rC4h
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int responseCode=httpConnection.getResponseCode(); <'}b*wUB
if(responseCode>=400) p<=(GY-
{ v@fe-T&0
processErrorCode(responseCode); O}K_l1
return -2; //-2 represent access is error "?.'{,Q
} Q%& _On
WxVn&c\
':4}O#
String sHeader; +}7Ea:K
>bfYy=/
RIy5ww}3|
for(int i=1;;i++) s&dO/}3uR]
{ MX!u$ei
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "U%n0r2
//Utility.log(in.readLine()); EjR_-8@FK
sHeader=httpConnection.getHeaderFieldKey(i); CxbSj,
if(sHeader!=null) *GbVMW[A>
{ RgB6:f,
if(sHeader.equals("Content-Length")) 'yPCZ`5H(
{ .3lGX`d{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .KLm39j(
break; nT.L}1@
} aO.\Qe+j
} w4e%-Ln
else bA@ /B'
break; =tr1*s{
} RzA2*]%a
} K*R)V/B/l
catch(IOException e){e.printStackTrace ();} `fBG~NDw
catch(Exception e){e.printStackTrace ();} -}{%Q?rYj
ixIV=#
0jxO |N2)
Utility.log(nFileLength); lx\qp`w
0U82f1ei
cGgM8
return nFileLength; }>MP{67Dm
} )uQ-YC('0
(^sh
L`9TB"0R+
//保存下载信息（文件指针位置） lGdM80f
private void write_nPos() ]2Sfkl0
{ ,CJAzGBS
try{ 4. 1rJa
output = new DataOutputStream(new FileOutputStream(tmpFile)); [YC=d1F5
output.writeInt(nStartPos.length); 9$7&URwSDI
for(int i=0;i<nStartPos.length;i++) &/Eg2
{ Lw*;tL<,
// output.writeLong(nPos); 9[cp7 Rcb
output.writeLong(fileSplitterFetch.nStartPos); fCgBH~w,9
output.writeLong(fileSplitterFetch.nEndPos); %1Bn_
} [Q4_WKI0T
output.close(); wYZT D*A2h
} C=fsJ=a5;
catch(IOException e){e.printStackTrace ();} iO!27y
catch(Exception e){e.printStackTrace ();} tIq>Oojdx
} "pt+Fe|@c;
Dt.0YKF
aSc{Ft/O
//读取保存的下载信息（文件指针位置） 6!P`XTTE
private void read_nPos() P DRnW
{ T}C2e! _O
try{ Dc08D4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (+|X<Bl:`
int nCount = input.readInt(); V,V*30K5
nStartPos = new long[nCount]; 6}ce1|mkg/
nEndPos = new long[nCount]; }$o*
for(int i=0;i<nStartPos.length;i++) IUOxGJ|rO
{ L2KG0i`+
nStartPos = input.readLong(); -x{dc7y2
nEndPos = input.readLong(); !7}IqSs
} JkZ50L
input.close(); 25UYOK}!
} _eGT2,D5r
catch(IOException e){e.printStackTrace ();} R)ERxz#
catch(Exception e){e.printStackTrace ();} w{pUUo:<
} <lUOJV{&\
_`H.h6h
K&*iw`
private void processErrorCode(int nErrorCode) z9[[C^C
{ YRPm^kW
System.err.println("Error Code : " + nErrorCode); 7 _`L$<-n
} J , V
pgT9hle/
t)` p@]j
//停止文件下载 m9Ax\lf
public void siteStop() OFA{ KZga
{ 3P1&;
bStop = true; ~ |6dH
for(int i=0;i<nStartPos.length;i++) :M06 ;:e
fileSplitterFetch.splitterStop(); (ab{F5
!BDUv(
2K;#Evn'j
} 7c-Gm R2
} iZaeoy
//负责部分文件的抓取 "NDxgJ%J35
**FileSplitterFetch.java X 7=fX~s
*/ 7|YN:7iA
package NetFox; @:Di`B_{
[]|;qHhC~(
D3`}4 A
import java.io.*; Br}h/!NU/
import java.net.*; \i!Son.<
,|+Gls
vv6?V#{
public class FileSplitterFetch extends Thread { j Fma|y
EM@;3.IO
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String sURL; //File URL 2#3^skj
long nStartPos; //File Snippet Start Position v!H:^!z
long nEndPos; //File Snippet End Position 7{f_fkbs
int nThreadID; //Thread's ID [*)Z!)
boolean bDownOver = false; //Downing is over ZPHXzi3j
boolean bStop = false; //Stop identical btH _HE
FileAccessI fileAccessI = null; //File Access interface c"7j3/p
FW8-'~
rz%<AF Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \ p4*$
{ -?<4Og[^
this.sURL = sURL; V >Hf9sZ
this.nStartPos = nStart; q@n^ZzTx
this.nEndPos = nEnd; [|[>}z:
nThreadID = id; q]\X~ 9#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SHD^}?-|
} . w H*sb
Y#FO5O%W
+E/y ~s
public void run() Q6IQV0{p
{ ,LZX@'5
while(nStartPos < nEndPos && !bStop) =p@8z /u
{ ;Wc4qJ.@
(vc|7DX M
HSN8O@dy
try{ 8!mc@$Z
URL url = new URL(sURL); I;7nb4]AmF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1tB[_$s
httpConnection.setRequestProperty("User-Agent","NetFox"); BByCMY
String sProperty = "bytes="+nStartPos+"-"; .R5y:O
httpConnection.setRequestProperty("RANGE",sProperty); 99=s4*xzM
Utility.log(sProperty); R^*K6Ad
dRI^@n
-h#mn2U~3r
InputStream input = httpConnection.getInputStream(); zP!J/}z
//logResponseHead(httpConnection); >O7~h[FN
p@YB?#Im
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byte[] b = new byte[1024]; PWB(5 f?
int nRead; 7\XE,;4>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9b;A1gu
{ QvLZg
nStartPos += fileAccessI.write(b,0,nRead); Sm-wH^~KA
//if(nThreadID == 1) FJNF%a)x2I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?":'O#E
} >u0w.3r#
C`V)VJM
T*~H m
Utility.log("Thread " + nThreadID + " is over!"); %UZVb V
bDownOver = true; ^j)BKD-
//nPos = fileAccessI.write (b,0,nRead); K93p"nHN
} ]"~51HQZ
catch(Exception e){e.printStackTrace ();} X"q!Y#)
} k~3.MU
} GiFXX
KCuGu}
B*1W`f
//打印回应的头信息 nkDy!"K
public void logResponseHead(HttpURLConnection con) |3hY6aty
{ =Z G:x<Hg
for(int i=1;;i++) |o<8}Nja6
{ tMp=-"
String header=con.getHeaderFieldKey(i); RDM`9&V!jp
if(header!=null) J*fBZ.NO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ILwn&[A0
Utility.log(header+" : "+con.getHeaderField(header)); otJ!UfpR8
else ($nrqAv4
break; ~8T(>!hE1h
} ,8MLoZ_
} BZv+H=b
v"^~&q0x
w}R~C
public void splitterStop() $gpG%Qj
{ fyWO
bStop = true; *&Lq!rFS
} Cx_Q:6T
!0,Mp@ j/
,TJD$^
} ;z~n.0'
sZ<9A Xk-E
CjIu[S1%
/* ]rN5Ao}2
**FileAccess.java .lgPFr6X
*//文件访问(定位，写) *Vw\'%p*
package NetFox; 8qEK+yi,
import java.io.*; Rli:x
A@*:<Hs%
U-kVNBs
public class FileAccessI implements Serializable{ Q7X3X,
B[4pX +f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k n[Y
RandomAccessFile oSavedFile; ;a{:%t
long nPos; Ez~'^s@
\dQx+f&t
U$dh1;
public FileAccessI() throws IOException h].~#*
{ COzyG.R.
this("",0); `(6r3f~XJ
} G rmzkNlN
kql0J|P?
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public FileAccessI(String sName,long nPos) throws IOException Em 6Qe
{ ORXm&z)
oSavedFile = new RandomAccessFile(sName,"rw"); P +"Y
this.nPos = nPos; jw}}^3.
oSavedFile.seek(nPos); l1U=f]
} JO<wK
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)Or.;
public synchronized int write(byte[] b,int nStart,int nLen) :'F}Dy
{ 38DT2<qC
int n = -1; 0$+fkDf
try{ G0O#/%%
oSavedFile.write(b,nStart,nLen); jn >d*9u
n = nLen; ^.k |SK`U
} BBG3OAyg_
catch(IOException e) Io4(f
{ @yXfBML?]
e.printStackTrace (); ofYlR|
} p Dx-2:}
e!Y0-=?nf#
B+C);WQ,
return n; 8}X5o]Mv
} uXDq~`S
g,o?q:FL
'0y9MXRT
} mbnV[
9Y>8=#.c
kF;DBN
/* HHX-1+L
**SiteInfoBean.java r:&`$8$
*/ 53-v|'9'
package NetFox; ;zM*bWh9
r<F hY
R8rfM?"W
public class SiteInfoBean { \0lnxLA
*BuUHjTv
@/ZF` :
private String sSiteURL; //Site's URL g;$Xq)Dd
private String sFilePath; //Saved File's Path ;S0Kh"A
private String sFileName; //Saved File's Name 8]4U`\k4
private int nSplitter; //Count of Splited Downloading File 63`{.yZ*z
V-n&oCS+f
SS`qJZ|w
public SiteInfoBean() F:y[@Yn
{//nSplitter的缺省值为5 F":r4`5D"K
//default value of nSplitter is 5 `qd+f{Q
this("","","",5); b=~i)`
} D+_oVob\
~4P%%b0,o
K=!Bh*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '13ZX:
{ ) ri}nL.
sSiteURL= sURL; p.+ho~sC,.
sFilePath = sPath; bAKiq}xG%i
sFileName = sName; Ig3;E+*>
this.nSplitter = nSpiltter; :qChMU|Y6
d*)CT?d&
nhIa175'
} kJWN.
#Z6'?p9
L?5Ck<!xG
public String getSSiteURL() hx/N1x
{ "4vy lHIo
return sSiteURL; cUTE$/#s
} %QKZT=}
#2r}?hP/m
/'31w9
public void setSSiteURL(String value) +w=AJdc
{ o9cM{ya/>
sSiteURL = value; 5M9 I,
} oB74y
DjSbyXvrg
'v]u#/7a
public String getSFilePath() lA>DS#_
{ f!O{%ev
return sFilePath; )(y)A[
} pb#?l6x$+
]4;PR("aU
}$bF 5&
public void setSFilePath(String value) <dW]\h?)
{ %W@v2
sFilePath = value; sKlDu
} ooUk O
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n_3O-X(
public String getSFileName() 2tal
{ ^pJ!isuqu
return sFileName; `7/Y@}n
} hWH:wB
:1Q!$ m
+la2n(CAK
public void setSFileName(String value) wn)JXR
{ ~I{n^Q/a
sFileName = value; +-E~6^>
} 1Bpv"67
<{~6}6o
;j4?>3
public int getNSplitter() i;!H!-sM
{ ID#I`}h.k
return nSplitter; 765p/**
} -?(E_^ng
r#xg#uoj
0_CN/5F
public void setNSplitter(int nCount) x' .:&z
{ }1>[
nSplitter = nCount; 2(/g}
} i+gQE!
} 3E3HL7
,\qs4&
;]_o4e6\p
/* ?.D3'qv
**Utility.java =zyC-;r!
*/ 5Kkdo!z
package NetFox; V*W;OiE_3
8P=o4lO+
C`5
public class Utility { OK\A</8r
w: >5=mfk
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public Utility() q7"7U=W0
{ /~^rr f
Yot?=T};3{
D$T%\ P
} nxr!`^Mne
ATR!7i\|
//线程睡眠 }fKSqB]T-
public static void sleep(int nSecond) =|9H
{ 9'r:~O
try{ R9B&dvG
Thread.sleep(nSecond); +"1NC\<*
} {l |E:>Q2
catch(Exception e) T8^5=/
{ q`pP$i:
e.printStackTrace (); |^A;&//
} .jj$Kh q]
} QR>gt;
U*3uq7
//日志 5< ja3
public static void log(String sMsg) u;`U*@
{ /tUy3myJ
System.err.println(sMsg); i\dc>C ;
} 3\Xbmq8}
0Q^Ikiv
CxfRVL`7
public static void log(int sMsg) A\#iXOd
{ Aj0Tfdxy
System.err.println(sMsg); ;$z$@@WC
} P LueVz
} uV=Qp1~
v'BZs
nB!&Zq
/* $#]]K
**TestMethod.java L:z?Zt)|
*/ rfq;%C
package NetFox; D&S26jrZ
# 0Lf<NZ
;s52{>&F]
public class TestMethod { 9k6r_G"
^.>jGI%rB
I}t#%/'YA
public TestMethod() }X=[WCKU
{ ///xx/weblogic60b2_win.exe ?yj6CL(,
try{ Pcw6!xH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $H-!j%hV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TYQwy*
SiteFileFetch fileFetch = new SiteFileFetch(bean); qkC/\![@
fileFetch.start(); VH[hsj
} Qm/u h
catch(Exception e){e.printStackTrace ();} DoeiW=
0fYj4`4=n
46 PoM
} 0A( +ZMd
="g*\s?r
K#U<ib-v
public static void main(String[] args) mL4]l(U
{ J2^'Xj_V
new TestMethod(); xl#LrvxI
} }oNhl^JC
} [h,QBz
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