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)); )<x9t@$
} M"z=114
for(int i=0;i<nEndPos.length-1;i++) >N^<Q4%2
{ Bc=(1ty)
nEndPos = nStartPos[i+1]; M+t)#O4
} Zg+.`>z
nEndPos[nEndPos.length-1] = nFileLength; 7gX32r$%V
} l$u52e!7
} '/GB8L
+w0Wg.4V
Ana[>wSZO@
//启动子线程 %|jS`kj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F}Zg3#
for(int i=0;i<nStartPos.length;i++) =Uk#7U"P
{ <$A,|m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >MYxj}I4{z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^B.Z3Y
nStartPos,nEndPos,i); -^NW:L$|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p\zqZ=s
fileSplitterFetch.start(); 9/"&6,
} A1zRzg4I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eC/{c1C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x8lBpr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~&:-c v
nEndPos = " + nFileLength); ?y|&Mz'XJ(
// fileSplitterFetch[nPos.length-1].start(); Zbo4{.#
RFw0u 0Nrz
7(/yyZQnZ
//等待子线程结束 g}~s"Sz
//int count = 0; bK "I9T #
//是否结束while循环 DY`0 `T
boolean breakWhile = false; 3Ei^WDJ
W[jg+|
0\i\G|5
while(!bStop) Gs#9'3_U5
{ &>-'|(m+2
write_nPos(); u^Cls!C
Utility.sleep(500); 8wWp+Hk
breakWhile = true; #19O5
mxqZj8VuH
Gza= 0
for(int i=0;i<nStartPos.length;i++) w/NT5
{ _;}$/
if(!fileSplitterFetch.bDownOver) } W]A`-Jv
{ %@QxU-k_
breakWhile = false; QFTiE1mGH
break; Pll%O@K
} 0d[O/Q`
} #8jiz+1 _
if(breakWhile) aPJTH0u
break; t %u0=V
L#`X ]E
#>yOp *
//count++; D[^K0<-Z
//if(count>4) i~x]!!
// siteStop(); EG4~[5[YgI
} Kmx4bp4
5kqI
G5hRx@vfrL
System.err.println("文件下载结束！"); km>ZhsqD
} /Ey%aA4v
catch(Exception e){e.printStackTrace ();} QXj#Brp
} ~{DJ,(N"n
{"jtR<{)
l_k:OZ
//获得文件长度 XY)X-K$
public long getFileSize() Q'U!
{ a[;L+
int nFileLength = -1; N5 sR
try{ [fCnq
URL url = new URL(siteInfoBean.getSSiteURL()); 0SD'&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _"*vj-{-y
httpConnection.setRequestProperty("User-Agent","NetFox"); b!t[PShw^
fFEB#l!oUb
5[g&0
int responseCode=httpConnection.getResponseCode(); \<I&utn
if(responseCode>=400) :V$\y up
{ L%[>z'Zp
processErrorCode(responseCode); ="G2I\
return -2; //-2 represent access is error [<r.M<3
} b4:{PD~Mh
K1YxF
jNbVp{%/S}
String sHeader; h5P ]`r
_G)A$6weU
;Q3[} ]su
for(int i=1;;i++) 62;xK-U
{ L=54uCv Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u ^#UsOt+
//Utility.log(in.readLine()); Sv=e|!3f[k
sHeader=httpConnection.getHeaderFieldKey(i); #n&/v'!\
if(sHeader!=null) y?cN
{ T5`ML'Dej
if(sHeader.equals("Content-Length")) G9&2s%lu.e
{ }r18Y6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IqlCl>_j
break; [qY yr
} BN(=LQ2["
} 1z|bQ,5
else xA^E+f:W_
break; yC ?p,Ci,
} G>?kskm
} 9PV]bt,
catch(IOException e){e.printStackTrace ();} C-ORI}o
catch(Exception e){e.printStackTrace ();} KKQT?/ {b
oFp1QrI3k8
+hKU]DP2;
Utility.log(nFileLength); "Plo[E
W*iTg%a\k
]Ndy12,M
return nFileLength; ;HYEJ3
} IAbQgBvUD
>r X$E<B\
NHUJ:j@
//保存下载信息（文件指针位置） 1mHS -oI9J
private void write_nPos() }.s%J\ckx
{ S/*\j7cj
try{ @gqZiFM)
output = new DataOutputStream(new FileOutputStream(tmpFile)); W4.w
output.writeInt(nStartPos.length); An}RD73!w
for(int i=0;i<nStartPos.length;i++) h+Lpj^<2a
{ {tOf0W|
// output.writeLong(nPos); Px-VRANZt
output.writeLong(fileSplitterFetch.nStartPos); QiA}0q3]0
output.writeLong(fileSplitterFetch.nEndPos); D HQxu4
} #Rfcp!
output.close(); 2\&3x}@
} s[eSPSFZ
catch(IOException e){e.printStackTrace ();} Q%~BD@Io
catch(Exception e){e.printStackTrace ();} Fnk@)1
} 3 ;"[WOv
3st?6?7|
A*:|d~
//读取保存的下载信息（文件指针位置） feS$)H9-
private void read_nPos() ;`xCfOY(
{ 2Y9u9;ah
try{ NKEmY-f;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wWx{#!W
int nCount = input.readInt(); iEI#J!~
nStartPos = new long[nCount]; G*_]Lz(N
nEndPos = new long[nCount]; FS)# v
for(int i=0;i<nStartPos.length;i++) >jiez,
{ sk07|9nU
nStartPos = input.readLong(); O..{wdZy
nEndPos = input.readLong(); ^AI02`c.
} RX{} UmU<
input.close(); kWa5=BW2f
} ,K@[+ R!
catch(IOException e){e.printStackTrace ();} trjpq{,[U
catch(Exception e){e.printStackTrace ();} I.Catm2
} GzaGTd.b
Is6}VLbB
5~UW=
private void processErrorCode(int nErrorCode) K:XP;#OsP
{ E_'H=QN c
System.err.println("Error Code : " + nErrorCode); 7jxx,#I:
} [f {qb\
X}]A_G
OqRRf
//停止文件下载 ]zAwKuIK
public void siteStop() #X1a v
{ %t6-wWM97
bStop = true; "doiD=b
for(int i=0;i<nStartPos.length;i++) N)D+FV29y
fileSplitterFetch.splitterStop(); h|PC?@jp
cR!M{U.q
T(Yp90'6
} G0Z5h
} Vg,nNa3
//负责部分文件的抓取 boDD?0.|
**FileSplitterFetch.java }:0ru_F)(4
*/ QL7.QG
package NetFox; f34/whD65
(f_YgQEL
S,5>/'fy0
import java.io.*; .9Cy<z
import java.net.*; ?[.8A/:5
Y+),c14#
C+M]"{Y+
public class FileSplitterFetch extends Thread { nhMxw@Z\
xDl; tFI
&uc`w{,Zs
String sURL; //File URL dG0zA D
long nStartPos; //File Snippet Start Position NZZy^p&O
long nEndPos; //File Snippet End Position M:oM(K+
int nThreadID; //Thread's ID $kN=45SR
boolean bDownOver = false; //Downing is over oj{CNa
boolean bStop = false; //Stop identical \1<|X].jNY
FileAccessI fileAccessI = null; //File Access interface MCEHv}W
7T6Zlp
5y g`TW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aaKf4}
{ uxDM #
this.sURL = sURL; EFx>Hu/[G
this.nStartPos = nStart; Fx.Ly]L
this.nEndPos = nEnd; Ye$j43b
nThreadID = id; sCt)Yp+8}B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <FU?^*~
} <)!,$]S
'Nt)7U>oC9
*U%3[6hm
public void run() H#V&5|K%
{ >EFWevT{
while(nStartPos < nEndPos && !bStop) Wq+GlB*
{ yZ[g2*1L
N>*+Wg$Ne
#\=7A
try{ _A!Fp0}`
URL url = new URL(sURL); "9c=kqkX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _4)z:?G5
httpConnection.setRequestProperty("User-Agent","NetFox"); &wY$G! P
String sProperty = "bytes="+nStartPos+"-"; RjvW*'2G
httpConnection.setRequestProperty("RANGE",sProperty); flC%<V%'-
Utility.log(sProperty); =&pLlG
Xj{fM\,"9
l"}_+5
InputStream input = httpConnection.getInputStream(); BK=w'1U
//logResponseHead(httpConnection); ToPjBvD
"OwVCym?
a,S;JF)v
byte[] b = new byte[1024]; <>{m+=gA
int nRead; MYjc6@=cR
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ojlyW})$%
{ *-5N0K<kQ
nStartPos += fileAccessI.write(b,0,nRead); ej}S{/<*n
//if(nThreadID == 1) 2yg6hR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j:'g*IxM_
} YK6'/2!
$qYP|W
F{a;=h#@Q
Utility.log("Thread " + nThreadID + " is over!"); t>?tWSNf
bDownOver = true; *n EkbI/
//nPos = fileAccessI.write (b,0,nRead); E}S%yD[
} 51y"#\7
catch(Exception e){e.printStackTrace ();} <nqv)g"u0
} mrnPZf i
} yCN_vrH>
:zKMw=
4L8hn4F
//打印回应的头信息 R^/SBrWve
public void logResponseHead(HttpURLConnection con) 0stc$~~v
{ HrsG^x
for(int i=1;;i++) D%yY&q;
{ bz#]>RD
String header=con.getHeaderFieldKey(i); =iKl<CqI$E
if(header!=null) Pb8@owG8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z dgS@g
Utility.log(header+" : "+con.getHeaderField(header)); Lm2!<<<
else v '+]T=
break; n:`f.jG |
} [C0v-
} 7LVG0A2>7
<OGG(dI
If,p!L
public void splitterStop() Q7XOO3<):
{ wTa u.Bo
bStop = true; ]n|Jc_Y
} m:?"|.]
(XVBH1p"
oXnaL)Rk
} eyyME c!
'{jr9Vh
f2;.He
/* :+PE1=v
**FileAccess.java ={ms@/e/T
*//文件访问(定位，写) {JP q.A
package NetFox; %?PFe}
import java.io.*; /v+)#[]>
\|S!g_30m
OA[e}Vn
public class FileAccessI implements Serializable{ 6qH0]7maI
<R /\nYXz
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >UaQ7CRo
RandomAccessFile oSavedFile; _5-h\RB)
long nPos; Df^F)\7!N?
'&![h7B
~pQN#C)CO>
public FileAccessI() throws IOException MWh Y&I+
{ a^p#M
this("",0); ^E.L8
} RTm/-6[N
9dhEQ=K{3
9VnBNuT
public FileAccessI(String sName,long nPos) throws IOException IQ I8v
{ rKrHd
oSavedFile = new RandomAccessFile(sName,"rw"); f 5v&4
this.nPos = nPos; k9;^|Cm k
oSavedFile.seek(nPos); c;$4}U4
} + t5SrO!`
Tf86CH=)5
pZ.b X
public synchronized int write(byte[] b,int nStart,int nLen) CP~ZIIip"
{ \x}\)m_7M<
int n = -1; m[B#k$
try{ @vt.Db
oSavedFile.write(b,nStart,nLen); 9RJF
n = nLen; lhGJ/By- -
} v4n< G-
catch(IOException e) Vb(b3
{ r0XEB,}
e.printStackTrace (); 2jFuF71
} u S1O-Q>
}xk(aM_
3#>W\_FY*D
return n; oBkhb
} sE pI)9
u=.8M`FxP
"B_3<RSL
} zsg\|=P
@KQ.tF*
0ra'H/>Ly
/* gw]%: WeH
**SiteInfoBean.java ;miif
*/ Q\N*)&Sd<M
package NetFox; G#n 4g:K
0X=F(,>9
<&3P\aM>
public class SiteInfoBean { 4o*i(W
?*fY$93O
vk92j?
private String sSiteURL; //Site's URL b6N[t _,
private String sFilePath; //Saved File's Path p{g4`o
private String sFileName; //Saved File's Name ??,[-Oi
private int nSplitter; //Count of Splited Downloading File }Kp!,
f+h\RE=BGt
y|5L%,i
public SiteInfoBean() I=y7$+7%
{//nSplitter的缺省值为5 ><<>4(eF p
//default value of nSplitter is 5 @NLcO}
this("","","",5); ZZY#.
} K~TwyB-h
e&}W#
IfK~~XYG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {zwH3)|Hn
{ n)e2?
sSiteURL= sURL; LhJUoX
sFilePath = sPath; srGOIK.
sFileName = sName; (pxH<k=Ah
this.nSplitter = nSpiltter; .kT]^rv ;
yLnQ9BXB&
t6DSZ^Zq
} +>Wo:kp3
K-0=#6?y4
DB/~Z
public String getSSiteURL() mmTpF]t ?`
{ o,6t:?Z
return sSiteURL; 0k]ApW
} ?jmP]MM
DrK]U}3fh"
0!hr9Y]Lx
public void setSSiteURL(String value) v(1 [n]y
{ Mog>W&U
sSiteURL = value; im<bo Mv
} 4t, 2H"M
r9[S%Def
$.PRav
public String getSFilePath() RM;a]g*
{ g#5R||r
return sFilePath; gHg=G+Q@
} G:AA>t
5\Q Tm;
p*;!5;OUR
public void setSFilePath(String value) 'nCVjO7o
{ AV5={KK
sFilePath = value; i,6OMB $
} Ykxk`SJ
7%*#M#(T
&jE\D^>ko
public String getSFileName() cOVj @z
{ '+88UFSq5
return sFileName; $ev+0m_
} B=|R?t(*
,aP6ct
;wn9 21r
public void setSFileName(String value) pY31qhoZ.
{ dGUP|O
sFileName = value; 0AQazhm
} 6G8No-#y
Q:A#4Z
nLN0zfhE#
public int getNSplitter() HpnF,4A>
{ )w7vE\n3
return nSplitter; 3~>-A=
} @j!,8JQEd
=:H-9
$vs],C"pX
public void setNSplitter(int nCount) Fs/CW\
{ CTIS}_CWd=
nSplitter = nCount; B)0/kY7c
} N!+=5!
} )/raTD
IZZAR
^'`b\$km-0
/* )|~K&qn`
**Utility.java x~e._k=
*/ 5X{|*?>T
package NetFox; Qi18q|l8v
] K$YtM^
7^eyO&4z
public class Utility { JipNI8\r
%3z[;&*3O
^ja]e%w#
public Utility() y=Y k$:-y
{ Zxebv#4
.n8R%|C5
(xfc_h*xA
} *:%&z?<Fw
!0;AFv`\
//线程睡眠 Y{} ub]i
public static void sleep(int nSecond) wHLQfrl0
{ E7X6RB b
try{ odhcD;^X1
Thread.sleep(nSecond); q/s-".%P
} 4.O)/0sU
catch(Exception e) XZE(& (s
{ x@NfN*?/+i
e.printStackTrace (); 7-744wV}Z
} (\6E.Z#
} g}_2T\$k
%1?t)Bg
//日志 Z(MZbzY7Hq
public static void log(String sMsg) CFpBosoFt^
{ j.=:S;
System.err.println(sMsg); ?8~l+m6s$
} 9UM)"I&k
H:.~! r
iw)gNQ%z4
public static void log(int sMsg) !>48`o^
{ 6z\!lOVjb
System.err.println(sMsg); a 0SZw
} v5[gFY(?
} Vn#}f=u\
Ed=/w6<
\K$\-]N+
/* ;\pr05
**TestMethod.java 8m+~HSIR
*/ F_@B ` ,
package NetFox; e{x>u(
b|i4me@
~XR('}5D
public class TestMethod { |lNp0b
bxE~tsM"@Y
aL(G0@(
public TestMethod() >CvhTrPI
{ ///xx/weblogic60b2_win.exe byM%D$R
try{ P^te
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $0V+<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xp|1yud
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^Mq/Cf_T
fileFetch.start(); @X/ 1`Mp
} }3lG'Y#Kpy
catch(Exception e){e.printStackTrace ();} Uh/=HNR
1>*oN
OY1bFIE
} @Ou H=<YN
Cu@q*:'
i!YfR]"}
public static void main(String[] args) _hY6NMw
{ ?o(284sV3
new TestMethod(); ip?]&5s
} qJG;`Ugl:
} d(^8#4
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