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)); -M{.KqyW
} ,OGXH2!h
for(int i=0;i<nEndPos.length-1;i++) 14U:.Q
{ rd#O ]
nEndPos = nStartPos[i+1]; 'JA<q-Gn
} M`1pze_A
nEndPos[nEndPos.length-1] = nFileLength; YzasT:EZN
} yL ?dC"c
} X:3W9`s)*
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WoYXXYP/E
//启动子线程 x^0MEsR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZA1u
for(int i=0;i<nStartPos.length;i++) \piHdVD
{ ^)\z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1m c'=S{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3rRN~$
nStartPos,nEndPos,i); PG@Uygahu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g#??Mz
fileSplitterFetch.start(); 86_`Z$ s
} {Z~5#<t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i.~*G8!DM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -chk\75
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5(+9( \x
nEndPos = " + nFileLength); %d%$jF`
// fileSplitterFetch[nPos.length-1].start(); 5Xe1a'n5]
-c_}^j
PPj_NV
//等待子线程结束 ZKk*2EK]2z
//int count = 0; /8$*{ay
//是否结束while循环 Uu}a! V
boolean breakWhile = false; .+.BNS
ggP#2I\
ZJZKCdT@
while(!bStop) Ei$@)qS/
{ bOvMXj/HV=
write_nPos(); >I*Qc<X91
Utility.sleep(500); q8Z,XfF^S
breakWhile = true; 8D)I~0\
v"Z`#Bi
<aScA`\B#
for(int i=0;i<nStartPos.length;i++) I7[F,xci
{ H0 %;t
if(!fileSplitterFetch.bDownOver) &IZthJqV
{ Ho_ 2zx:8b
breakWhile = false; #0F6{&; M
break; ue/GB+U
} >}?4;:.=
} jdEqa$CXG
if(breakWhile) OS.oknzZZ
break; -nsI5\]
O]/BNacS
jf|5}5kSlf
//count++; "&Y5Nh
//if(count>4) A/xo'G
// siteStop(); sy s6 V?
} <dd(i
v[}g+3a
)ld !(d=
System.err.println("文件下载结束！"); /-mo8]J#2~
} h^`!kp
catch(Exception e){e.printStackTrace ();} DjK
} N8-!}\,
X-mhz3Q&a
O! t> @%)
//获得文件长度 i#RT4}l"a
public long getFileSize() BY&+fKae
{ B(z?IW&
int nFileLength = -1; zHT22o56X
try{ GQR|t?:t
URL url = new URL(siteInfoBean.getSSiteURL()); :RqTbE4B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1638U1
httpConnection.setRequestProperty("User-Agent","NetFox"); |+|q`SwJ
13lJq:bM
bt2`elH|
int responseCode=httpConnection.getResponseCode(); 8rXQK|A
if(responseCode>=400) vnrP;T=^
{ m%[Ul@!V
processErrorCode(responseCode); yM}Wg~:D:
return -2; //-2 represent access is error }5I+VY7a
} T*'?;u
F79!B
th 9I]g^=t
String sHeader; z;F6:aBa
foi@z9
10C,\
for(int i=1;;i++) 5VXI/Lw#
{ MeSF,*lP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <%~`!n,t0
//Utility.log(in.readLine()); Uql|32j
sHeader=httpConnection.getHeaderFieldKey(i); I<["ko,t@?
if(sHeader!=null) y!,Ly_x$@
{ |d@%Vb_
if(sHeader.equals("Content-Length")) qVpV ZH!
{ Q`Z=}^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /&`sB|
break; R[l9f8
} [J`%iU
} 5R?[My
else 2(<2Gnpl
break; 2c Pd$j
} C(Bh<c0@
} Vo@gxC,
catch(IOException e){e.printStackTrace ();} Wvg+5Q
catch(Exception e){e.printStackTrace ();} {4%B^+}T
ZYi."^l
KO~_
Utility.log(nFileLength); AD** 4E
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q3CcXYY
return nFileLength; \m\E*c ):
} ?hXeZB+b4
)$.::[pNA
dE`a1H%
//保存下载信息（文件指针位置） "k0bj>
private void write_nPos() ^ |xSU_wa
{ a___SYl 'K
try{ mHiV};$
output = new DataOutputStream(new FileOutputStream(tmpFile)); ) Ekd
output.writeInt(nStartPos.length); ++HHUM
for(int i=0;i<nStartPos.length;i++) 8c6dTT4
{ t,f)!D$
// output.writeLong(nPos); qt.G_fOz
output.writeLong(fileSplitterFetch.nStartPos); KliMw*5(
output.writeLong(fileSplitterFetch.nEndPos); P Tc@MH)
} )37.H^7
output.close(); MHm=X8eg
} G~ldU: ?
catch(IOException e){e.printStackTrace ();} Xq"_^
catch(Exception e){e.printStackTrace ();} %ja8DRQ.
} ;?*`WB
U@6bH@v5
5Dhpcgq<<
//读取保存的下载信息（文件指针位置） >\/H2j
private void read_nPos() BeNH"Y:E
{ ~"Kf+eFi
try{ U:a-Wi+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FLqF!N\G
int nCount = input.readInt(); w6-A-M6hD
nStartPos = new long[nCount]; _4#8o\
nEndPos = new long[nCount]; B;3lF;3`
for(int i=0;i<nStartPos.length;i++) u(Y! _
{ L,m'/}$
nStartPos = input.readLong(); 5Oa`1?C1
nEndPos = input.readLong(); >I~$h,
} =&5^[:ksB
input.close(); iEA$`LhO\A
} *tWZ.I<<
catch(IOException e){e.printStackTrace ();} QM"\;l??
catch(Exception e){e.printStackTrace ();} 9L`5r$/
} !zu YO3:
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private void processErrorCode(int nErrorCode) z ?3G`
{ .IO_&^
System.err.println("Error Code : " + nErrorCode); !mM`+XH
} B"07:sO
U#u=9%'
a5)<roWQ
//停止文件下载 gB&8TE~Y
public void siteStop() MRI`h.
{ ^:Mal[IR
bStop = true; B7*^rbI:X
for(int i=0;i<nStartPos.length;i++) k\ 2.\Lwb
fileSplitterFetch.splitterStop(); ;fdROI
C1x"q9|\`
"vH>xBR[%
} oHW:s96e
} ~]d3 f
//负责部分文件的抓取 Epl\(
**FileSplitterFetch.java aX)k(*|
*/ d,hKy2
package NetFox; -msfiO
0xSWoz[i6~
(=T%eJ61
import java.io.*; VV$$t;R/
import java.net.*; "-WEUz
hHu?%f*
Y]9AC
public class FileSplitterFetch extends Thread { aw3 oG?3I
*(?tf{
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String sURL; //File URL M9t`w-@_w
long nStartPos; //File Snippet Start Position lCX*Q{s22
long nEndPos; //File Snippet End Position 0bcbH9) 1q
int nThreadID; //Thread's ID 8B*XXFy\
boolean bDownOver = false; //Downing is over 2fa1jl
boolean bStop = false; //Stop identical |e]2 >NjQa
FileAccessI fileAccessI = null; //File Access interface }Qqi013E L
qgk-[zW#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kdam]L:9
{ O1 KT
this.sURL = sURL; ,drcJ
this.nStartPos = nStart; W/\M9
this.nEndPos = nEnd; k>'c4ay290
nThreadID = id; /Cl=;^)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $Y\-X<gRH
} Za>0&Fnf
b.4H4LV
4(hHp6}b
public void run() p bT sn
{ s (hJ *
while(nStartPos < nEndPos && !bStop) JtB]EvpL}
{ NCKhrDd&
k7R}]hq]""
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try{ x3QQ`w-
URL url = new URL(sURL); U7(t >/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v?)u1-V0
httpConnection.setRequestProperty("User-Agent","NetFox"); "fq8)
String sProperty = "bytes="+nStartPos+"-"; xV}ybRKV
httpConnection.setRequestProperty("RANGE",sProperty); u~-,kF@
Utility.log(sProperty); ~R$Ko(N
#A@d;U%
y?}R,5k
InputStream input = httpConnection.getInputStream(); 03$lgDQ
//logResponseHead(httpConnection); SR<*yO
Cbq|<p# #o
DH*=IzcJf
byte[] b = new byte[1024]; sZ7RiH+I
int nRead; "AayU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7XDze(O5
{ vrr`^UB2
nStartPos += fileAccessI.write(b,0,nRead); 7Gs0DwV
//if(nThreadID == 1) Qt VZ)777
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N =0R6{'
} _XP3|E;I/
c9<&+
1^HUu"Kt
Utility.log("Thread " + nThreadID + " is over!"); by{ *R
bDownOver = true; mz<wYV*
//nPos = fileAccessI.write (b,0,nRead); ZBf9Upg
} (F.vVldBy
catch(Exception e){e.printStackTrace ();} 2{gd4Kt6.
} GO|EeM!iB
} 2TZ+R7B?
(+=TKI<=
i(pevu
//打印回应的头信息 (d@ =
public void logResponseHead(HttpURLConnection con) Z9+xB"q2
{ >8>}o4Q/X
for(int i=1;;i++) puPYM"
{ P:3%#d~q
String header=con.getHeaderFieldKey(i); [ ]LiL;A&
if(header!=null) SB<09|2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aDreN*n
Utility.log(header+" : "+con.getHeaderField(header)); Hc"FW5R
else 0s%rd>3
break; S}T*gUO
} AWqc?K@
} d mj T$a|
-Z/'kYj?U
g12mSbf=9
public void splitterStop() ti}g?\VT
{ Ksu_4dE
bStop = true; #ivN-WKCl
} z$q:Yg
=C[2"Y4JK0
)ZP-t!).G#
} #!n"),3
V,W":&!x
Gf|qc>j.b
/* e[8AdE
**FileAccess.java nnm9pnx
*//文件访问(定位，写) e#uk+]
package NetFox; ?g5u#Q>!
import java.io.*; t;~H6
fcC?1M[BP~
; {P"~(S%
public class FileAccessI implements Serializable{ PilV5Gg
wv~?<DF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W,[b:[~v
RandomAccessFile oSavedFile; tluyx
long nPos; o.Jq1$)~y
3V"y|q
~D9VjXfL)
public FileAccessI() throws IOException #Ang8O@y
{ oiS>:de%tc
this("",0); N]k(8K
} pNHO;N[&
:cmQ w
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public FileAccessI(String sName,long nPos) throws IOException LcA~a<_
{ 9_6.%qj&
oSavedFile = new RandomAccessFile(sName,"rw"); l/JE}Eg(
this.nPos = nPos; l u^fKQ
oSavedFile.seek(nPos); dX58nJ4u
} R`RLq1WA
gyI(O>e
DM-8azq $
public synchronized int write(byte[] b,int nStart,int nLen) E/MNz}+
{ iE|qU_2Y
int n = -1; U~mv1V^.
try{ Cyb-}l
oSavedFile.write(b,nStart,nLen); vlD!YNy
n = nLen; ;Ly(O'9
} CTbz?Kn
catch(IOException e) NjCdkT&g
{ jDp]}d|f)
e.printStackTrace (); C^hHt,&
} s{-`y`JP
"rjqDpH
vu%:0p`K
return n; }@*Me+
} RsYn6ozb
Sv7_-#SW<(
Q}J'S5%
} 4DVkycM
5dVSir
Dj<]eG]
/* >+[uV^2[
**SiteInfoBean.java ~h~K"GbC?
*/ Y2 &N#~l*
package NetFox; 3gW4\2|T
%`%xD>![
CjzfU*G
public class SiteInfoBean { rAdYBr=0
74c1i
G\\zk
private String sSiteURL; //Site's URL !@ml^&hP
private String sFilePath; //Saved File's Path d9XX^nY.
private String sFileName; //Saved File's Name K_iy^|0)5]
private int nSplitter; //Count of Splited Downloading File W^2Q"c#7F
u"K-mr#$[o
l-yQ3/:
public SiteInfoBean() &(fB+VNrOH
{//nSplitter的缺省值为5 Mj&f7IUO
//default value of nSplitter is 5 0gBD
this("","","",5); ?Uzs^rsb
} 29K09 0f
=nEl m*E
6&=xu|M<x=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DRD%pm(
{ }Po&6^
sSiteURL= sURL; `zHtfox!
sFilePath = sPath; v7O&9a;
sFileName = sName; rN)T xH&*p
this.nSplitter = nSpiltter; p+ymtPF
yV:DR
@]Ye36v0#L
} }%EQ
$4`RJ{ZJw]
)< ~1AL
public String getSSiteURL() aWVJx@f
{ YJ]]6 K+
return sSiteURL; 7-+X -Y?
} v709#/cR
lhAwTOn`Q
4J2NIFZ
public void setSSiteURL(String value) ~130"WQ;
{ +nRO<
sSiteURL = value; KcVCA
} z2og&|uT
i% k`/X;
3|RfX
public String getSFilePath() i/*&;
{ *&>1A A
return sFilePath; /ocdAW`0
} I ms?^`N
Wx~0_P
Mw7 ~:O`
public void setSFilePath(String value) J%EbJ5p<QF
{ Y_S^B)y
sFilePath = value; -yOrNir}W
} wFpt#_fS
nJ.pPzH2g
YY]JjMkU
public String getSFileName() A[v]^pv'
{ =0`"T!1
return sFileName; R>[2}R30
} GDP@M)~6*
gKcP\m
!Pt|Hk dr
public void setSFileName(String value) .Nr}V.?57
{ |vA3+kG
sFileName = value; or\ 2)
} "m):"
Nqp%Z7G
g=Q#2/UQ<
public int getNSplitter() EUmQn8
{ H:4r6-{
return nSplitter; e2UbeP
} :gVz}/C.@
pNr3u
,*a8]L
public void setNSplitter(int nCount) d4/snvq
{ "m0>u,HmI
nSplitter = nCount; c'&3[aa
} . [+ObF9=
} ' ~lC85
AF ZHS\
\06fP4?
/* 7EOn4I2@[
**Utility.java /cexd_l|f
*/ h"Yi'
package NetFox; h|mh_T{+
E {4/$}
M' "S:
public class Utility { a"EP`
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/@lXQM9T
public Utility() x&+/da-E/5
{ ~0>g 4 D.
qxG@Zd
YMj z,N
} fI`6]?W
^;$a_eR
//线程睡眠 |L.QIr,jCC
public static void sleep(int nSecond) bk}.^m!
{ r^n%PH<
try{ ' ]l,
Thread.sleep(nSecond); ;t:B:4r(j
} |0ACapp!
catch(Exception e) H5S>|"`e`e
{ NjMbQM4
e.printStackTrace (); M-,vX15S
} K;,n?Q w
} lJpD>\$}@R
R#`hT
//日志 P7&a~N$T6W
public static void log(String sMsg) m!er"0
{ {vx{Hwyv
System.err.println(sMsg); CA7tI >y_
} K!7o#"GM
<oS2a/Nd
"uDLty?*k
public static void log(int sMsg) V?kJYf(<
{ D@rOX(m
System.err.println(sMsg); *Tl"~)'t~
} rOm)s'
} fa8vY
ZtlF]k:MV
dz5a! e [
/* w[I%Id;E
**TestMethod.java X<Rh-1$8F
*/ 6 KP
package NetFox; <8|vj2d2
?y>xC|kt
puG$\D-[
public class TestMethod { _*0!6?c
KRd.Ubs -
%0YwaxXPn7
public TestMethod() , b ,`;I
{ ///xx/weblogic60b2_win.exe ?5K.#>{
try{ L)H7~.Dj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >:4}OylhM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bLUn>ch
SiteFileFetch fileFetch = new SiteFileFetch(bean); \om$%FUP
fileFetch.start(); %a<N[H3NV@
} _}:9ic]e
catch(Exception e){e.printStackTrace ();} G#ZU^%$M,
XE[~! >'
K%P$#a
} +yiGZV/X
5rRYv~+
|lm
public static void main(String[] args) 3kx/Q#
{ +v2Fr}
new TestMethod(); hC4##pAa
} Q9tBHz
} *.K+"WS%
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