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)); b`~wGe
} hu@7?f_"L/
for(int i=0;i<nEndPos.length-1;i++) h=+$>_&:
{ shFc[A,r}
nEndPos = nStartPos[i+1]; >L>+2z
} c@du2ICUc
nEndPos[nEndPos.length-1] = nFileLength; W|R-J
} Z85|I.mr
} Fb_S&!
tYe:z:7l?<
]((i?{jb(
//启动子线程 j6>tH"i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?pwE0N^
for(int i=0;i<nStartPos.length;i++) IgX4.]W5
{ Yp5L+~J[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SG'JE}jzO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )"u:ytK{
nStartPos,nEndPos,i); T9jw X:n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sdr.u
fileSplitterFetch.start(); (_+;R
} }Ik1bkK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), la, h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OyVm(%Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \ P/W8{
nEndPos = " + nFileLength); [)|+F wJ
// fileSplitterFetch[nPos.length-1].start(); ti_u!kNv
]+%=@mWYs
uHvaZMu
//等待子线程结束 8wFn}lw&
//int count = 0; <DmTj$
//是否结束while循环 pj|X]4?wdI
boolean breakWhile = false; @ss):FwA
=,:K)
Lb~\Yn'z
while(!bStop) o)I/P<
{ )f*Iomp]@
write_nPos(); =5s$qb?#
Utility.sleep(500); Y!n'" *J>
breakWhile = true; o#{#r@,i
"c Pz|~
8S>>7z!U
for(int i=0;i<nStartPos.length;i++) ^H=o3#P~L
{ R^tcr)(
if(!fileSplitterFetch.bDownOver) A{`]&K1u
{ O/9fuEF
breakWhile = false; S0xIvzS
break; l l:jsm
} - L`7+
} Sx&mv.?X
if(breakWhile) V9{B}5KC
break; v" FO
fsI`DjKi)
?>?ZAr
//count++; e"_"vbk
//if(count>4) 3- )kwy6L
// siteStop(); l $Zs~@N
} m X:bA5db
8S=c^_PJ
-W^2*w
System.err.println("文件下载结束！"); *a4 b
} )"~=7)~<^
catch(Exception e){e.printStackTrace ();} OR~GOv|
} yu_gNro L
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y`+<X{V5L
//获得文件长度 z1qUz7
public long getFileSize() YiNo#M91
{ Esa6hU#
int nFileLength = -1; .-%oDuB5zF
try{ U]mO7HK
URL url = new URL(siteInfoBean.getSSiteURL()); auoA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KM@`YV_"g
httpConnection.setRequestProperty("User-Agent","NetFox"); g4T3?"xMB_
qKx59
04[)qPPS
int responseCode=httpConnection.getResponseCode(); '%$-]~
if(responseCode>=400) J ZNyC!u
{ bZnDd
processErrorCode(responseCode); [$H( CH`
return -2; //-2 represent access is error BDnBBbBrz
} 8ZzU^x
~Gwas0eNa
@OrXbG7&>#
String sHeader; ]X4RnV55Q
GMt)}Hz
#Z#_!o
for(int i=1;;i++) *X0K2|
{ +*Q9.LjV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X.:_"+I;
//Utility.log(in.readLine()); #C'o'%!(
sHeader=httpConnection.getHeaderFieldKey(i); YU*46 hA1B
if(sHeader!=null) }$w4SpR
{ #SK#k<&P
if(sHeader.equals("Content-Length")) [v~Uy$d\
{ /XbY<pj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >^sz5d+X
break; d+1L5}Jn
} 6Lav.x\W
} zl,bMtQ
else Vl&+/-V
break; ~x9 W{B]
} )sMAhk|
} F9ZOSL 8Q
catch(IOException e){e.printStackTrace ();} (4E.Li<O
catch(Exception e){e.printStackTrace ();} k?z [hZg0
XtnIK
tOu90gu
Utility.log(nFileLength); xuw//F
LS*{]@8q
kJVM3F%
return nFileLength; G}Q}H*
} ]JGKL5~p
,dGFX]P
D>,$c
//保存下载信息（文件指针位置） Oct\He\.
private void write_nPos() F&>T-u-dog
{ w}]3jc84
try{ !W(/Y9g#
output = new DataOutputStream(new FileOutputStream(tmpFile)); )< X=z
output.writeInt(nStartPos.length); 9RbGa Y&
for(int i=0;i<nStartPos.length;i++) ;7B2~zL
{ WW,r9D:/
// output.writeLong(nPos); B'P,?`
output.writeLong(fileSplitterFetch.nStartPos); /zDSlj<c
output.writeLong(fileSplitterFetch.nEndPos); GN}9$:
} )x9nED{
output.close(); '_Hb}'sFI
} ?eYchVq
catch(IOException e){e.printStackTrace ();} Q_UCF'f;}
catch(Exception e){e.printStackTrace ();} >TH-Q[
} -wG[>Y
ba8-XA_~U
& y 2GQJE
//读取保存的下载信息（文件指针位置） ^5^ zo~^o
private void read_nPos() 6+{nw}e8
{ y.TdWnXx
try{ f%(e,KgW=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @et3}-c
int nCount = input.readInt(); mt&JgA/
nStartPos = new long[nCount]; q%)*,I<
nEndPos = new long[nCount]; B7x"ef
for(int i=0;i<nStartPos.length;i++) bb0{-T)1
{ "pKGUM
nStartPos = input.readLong(); )f_"`FH0d
nEndPos = input.readLong(); [1[[$ Dr
} !W6
input.close(); `Q!FMv6Y^
} BLYk <m
catch(IOException e){e.printStackTrace ();} gE]a*TOZk
catch(Exception e){e.printStackTrace ();} rE' %MiIK
} R4K eUn"
JUUF^/J
u3ri6Y`
private void processErrorCode(int nErrorCode) o<eWg
{ u9y-zhj_$
System.err.println("Error Code : " + nErrorCode); 83O^e&Bt
} nk?xNe4
C[/Uy
D%";!7u
//停止文件下载 (B?xq1Q
public void siteStop() WZy6K(18"'
{ w7]p9B
bStop = true; V'BZ=.=
for(int i=0;i<nStartPos.length;i++) c)P%O
fileSplitterFetch.splitterStop(); ,"lBS?
tg%WVy2
TVEF+t
} d .lu
} L"zgBB?K6
//负责部分文件的抓取 H2tpP~!G
**FileSplitterFetch.java =;-ju@d
*/ &4$43\(D
package NetFox; WFc[F`b
uEi.nSp)S
Ga/\kO)x_
import java.io.*; ;@;ie8H
import java.net.*; 1'._SMP
uu46'aT
eNk!pI7g
public class FileSplitterFetch extends Thread { J$=b&$I(
68G] a N3
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String sURL; //File URL Y_iF$m/R
long nStartPos; //File Snippet Start Position >C d&K9H
long nEndPos; //File Snippet End Position { 'mY>s7
int nThreadID; //Thread's ID M97p.;;
boolean bDownOver = false; //Downing is over Js2_&?}3f
boolean bStop = false; //Stop identical q,h.W JI
FileAccessI fileAccessI = null; //File Access interface FO)nW:8]
Mm[1Z;H
q8yJW-GA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException VlXy&oZ
{ nhaoh!8A6
this.sURL = sURL; #i#.tc
this.nStartPos = nStart; O5n]4)<
this.nEndPos = nEnd; 5^qp&
nThreadID = id; j`-y"6)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MM)/B>cQt
} 2o7C2)YT$
&=t(NI$
gJfL$S'w
public void run() |4*2xDcl
{ S{|)9EKw
while(nStartPos < nEndPos && !bStop) 1+ARV&bc
{ G6ES]
5oyMR_yl
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try{ +OP:"Q_#
URL url = new URL(sURL); (ZR"O8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hl~F1"q)
httpConnection.setRequestProperty("User-Agent","NetFox"); ?4||L8j2^
String sProperty = "bytes="+nStartPos+"-"; uWT&`m_(2
httpConnection.setRequestProperty("RANGE",sProperty); w)>z3Lm
Utility.log(sProperty); v-aq".XQ
C3h!?5
?{Z0g+B1
InputStream input = httpConnection.getInputStream(); H%gD[!^
//logResponseHead(httpConnection); c|a|z}(/J
]ZATER)jq
bo/!u s#
byte[] b = new byte[1024]; cf3c+.o
int nRead; DLM9o3/*J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vrDRSc6_
{ S.4YC>E
nStartPos += fileAccessI.write(b,0,nRead); 6KTY`'I
//if(nThreadID == 1) ]>i0;RME
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .T X& X
} #al^Uqd
[\F,\
F<WX\q
Utility.log("Thread " + nThreadID + " is over!"); i(kK!7W35
bDownOver = true; LP_F"?4
//nPos = fileAccessI.write (b,0,nRead); xT8"+}
} <TuSU[]
catch(Exception e){e.printStackTrace ();} F}[;ytmUS
} *s4!;2ZhsU
} ]vFmY
R/YL1s
.AW*7Pp`f
//打印回应的头信息 Z.(x|Q9
public void logResponseHead(HttpURLConnection con) O{R5<"g
{ kl9z;(6p
for(int i=1;;i++) DNe^_v)]|
{ cyE2=
String header=con.getHeaderFieldKey(i); dVfDS-v!
if(header!=null) o>tT!8rH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #4u; `j"4=
Utility.log(header+" : "+con.getHeaderField(header)); va;wQ~&
else mm`3-F|
break; B6oAW,3
} bm.H0rHR4
} R<Tzt'z
:i$Z
;N|>pSzmL
public void splitterStop() jwox?]f+
{ $)~]4n=
bStop = true; 6f>HE'N
} ISmnZ@
e8.bH#
I,;)pWX=@
} iH=@``Z
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/* 78-:hk
**FileAccess.java m+"%Jd{q
*//文件访问(定位，写) zL'n J
package NetFox; )^+$5OR\c
import java.io.*; gjV&X N
8hg(6 XUG
*1n:
public class FileAccessI implements Serializable{ c[$oR,2b13
=I1@O9}+i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ='j
RandomAccessFile oSavedFile; j@2 hI,+
long nPos; +h/$_5
vrGNiGIi[
HApP*1J^c
public FileAccessI() throws IOException 8Bvjj|~ (@
{ DI7trR`
this("",0); qC&<U
} \=<.0K A~
LzfLCGA^
4 #N#[;M
public FileAccessI(String sName,long nPos) throws IOException L"a#Uu8
{ 7d*<'k]{,
oSavedFile = new RandomAccessFile(sName,"rw"); 2h!3[{M\
this.nPos = nPos; d?mdw ?|
oSavedFile.seek(nPos); ')+EW" e
} lI 8"o>-~
;ORy&H aKl
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public synchronized int write(byte[] b,int nStart,int nLen) P,wJ@8lv
{ ?cvv!2B]T
int n = -1; 9maw+c!~
try{ a#1X)ot
oSavedFile.write(b,nStart,nLen); S]>_o"|HV
n = nLen; LtQy(F%8/
} ^cNP?7g7
catch(IOException e) UgP5^3F2
{ ZS-9|EA<
e.printStackTrace (); w~9gZ&hdp
} f19 i !
U uysG\
"J9+~)e^!
return n; -|lnJg4
} 0-9&d(L1g
=aCv Xa&,
-=RXhE_{
} okYsjK5
JnZxP> 2B
]k8XLgJ
/* r\]WDX!`
**SiteInfoBean.java BK{8\/dg
*/ J L3A/^
package NetFox; (F)zj<{f
mf3G$=[
2'_sGAH
public class SiteInfoBean { 01Aa.i^d(
QUNsS9
Eq?o/'e
private String sSiteURL; //Site's URL 0KZ 3h|4lP
private String sFilePath; //Saved File's Path |] YT6-?.
private String sFileName; //Saved File's Name $`
private int nSplitter; //Count of Splited Downloading File -[F^~Gv|;
&jJgAZ!
DlP}Fp{
public SiteInfoBean() CUG6|qu
{//nSplitter的缺省值为5 g41LpplX
//default value of nSplitter is 5 y8L:nnSj
this("","","",5); oGM.{\i
} @sDd:>t
Z-Uq89[HZ
+]6 EkZO
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) GA|q[<U
{ 84{<]y
sSiteURL= sURL; v/.2Z(sZ
sFilePath = sPath; :$WRV-
sFileName = sName; X;1q1X)K
this.nSplitter = nSpiltter; Fh"S[e
?YS`?Rr
{T IGPK
} \DHCf4,
uPqPoI>N!
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public String getSSiteURL() NE! Xt<A
{ _CZ*z
return sSiteURL; gW, ET
} N>~*Jp2;
56)B/0=
8(A:XQN"h
public void setSSiteURL(String value) "P|G^*"~2
{ jfWIPN
sSiteURL = value; O$$N{
} WULj@ds\~
K'tz_:d|
7HF\)cz2
public String getSFilePath() 0I k@d'7
{ DK-=Q~`!
return sFilePath; H5 -I}z
} u Qj#U m8
k >MgrtJI
ux }DWrR
public void setSFilePath(String value) ZTun{Dw{
{ ~}5(J,1!
sFilePath = value; ,lUo@+
} &sRyM'XI
c:iMbJOn#
+VeLd+Q}
public String getSFileName() 4>|5B:
{ ~\^8 ^
return sFileName; @@$ _TaI
} 2rH6ap
)CB?gW
A~6 Cs
public void setSFileName(String value) Glwpu-@X
{ lN&GfPP6
sFileName = value; iaC$K@a{
} ~% c->\Q
A gPg0(G
Grqs*V &|g
public int getNSplitter() @4|/| !
{ Z`%;bP:
return nSplitter; =Dz[|$dV
} 4{R`
`MD/CFl4
y6s$.93
public void setNSplitter(int nCount) E%e-R6gl
{ !d^`YEfE
nSplitter = nCount; .jKO 6f
} }>w; +XU
} NplSkv
BpCSf.zZ
n&fV3[m`2
/* 7^L&YVW
**Utility.java +R_U
*/ 4Y2>w
package NetFox; 87Kx7CKF"
G$j8I~E@
{x:IsQZ
public class Utility { u *< (B
yV. P.Q
:-Pj )Y{I
public Utility() H,}?YW
{ |2# Ro*
}FXRp=s
4Bn+L,}.
} ;w>B}v;RE
lySaJd
//线程睡眠 `FwAlYJK
public static void sleep(int nSecond) <'-me09C*
{ *l//r V?l
try{ H]e 2d|
Thread.sleep(nSecond); 3Z0\I\E
} S6mmk&n
catch(Exception e) 5*AKl< Jl
{ .tNB07=7
e.printStackTrace (); m%&B4E#3T
} )sHPIxHI
} 'UxA8i(
W}RR_Gu
//日志 U~m.I
public static void log(String sMsg) wLbngO=VG
{ je-s%kNlJ
System.err.println(sMsg); r.^&%D
} :+Kesa:E
@XmkIm
RHbwq]
public static void log(int sMsg) [w f12P
{ ;"Y6&YP<
System.err.println(sMsg); JyO lVs<T
} 6qlr+f
} "+&<Qd2
I>aa'em
Ne 4*MwK
/* YqgW8EM
**TestMethod.java Ysu/7o4
*/ Dfia=1A
package NetFox; ^%pwyY\t
OB22P%
yxbTcZ
public class TestMethod { }c%y0)fL
vuBA&j0C
Kf#!IY][
public TestMethod() 9 NQq=@
{ ///xx/weblogic60b2_win.exe Phu| hx<
try{ ]?{lQ0vw'w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VKz<7K\/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c ?XUb[
SiteFileFetch fileFetch = new SiteFileFetch(bean); (+dRD]|T
fileFetch.start(); M7,MxwZ0k
} 0h4}RmS
catch(Exception e){e.printStackTrace ();} -QDgr`%5
J_|x^
()?co<@(l
} dRm'$ G9
B}+9U
nX%'o`f
public static void main(String[] args) tYZGf xj
{ 7"ps#)O
new TestMethod(); r:4IKuTR
} vp-7>Wj
} 4&hqeY3
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