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)); bF'^eR
} C"I:^&sL
for(int i=0;i<nEndPos.length-1;i++) 8Ilg[Drj*
{ iv*Ft.1t
nEndPos = nStartPos[i+1]; sILkTzsw
} S/?KC^JP
nEndPos[nEndPos.length-1] = nFileLength; u[_~ !y
} b NBpt}$
} V3'QA1$
h-Q3q:
=Zcbfo_&
//启动子线程 $4\,a^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]C =+
for(int i=0;i<nStartPos.length;i++) &xlz80%
{ *OT6)]|k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YH( 54R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z (,%<oX
nStartPos,nEndPos,i); VemgG)\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fT-yY`
fileSplitterFetch.start(); e5_:15%R\
} G9.+N~GZ.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }>\+eG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %G& Zm$u=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }kaU0 P
nEndPos = " + nFileLength); =X?jId{
// fileSplitterFetch[nPos.length-1].start(); s5X .(;+
\7QAk4I~
R<+K&_
//等待子线程结束 !tkP!%w
//int count = 0; 2G'Au}q0n
//是否结束while循环 wD-(3ZVd4
boolean breakWhile = false; aO9a G*9T
@3/.W+
6@TGa%:G
while(!bStop) $\xS~w
{ ewYZ} "o
write_nPos(); iol.RszlZ|
Utility.sleep(500); &y?L^Aq
breakWhile = true; FTx&] QN?
Y3+GBqP
jrGVC2*rD
for(int i=0;i<nStartPos.length;i++) )E<<
{ f)p c$~B
if(!fileSplitterFetch.bDownOver) -v*wT*I1
{ &<Bx1\ ~V
breakWhile = false; 0Bx.jx0?
break; )]"aa_20]
} Zs _Jn
} I^pD=1Y]
if(breakWhile) "pb,|U
break; IG?044Y
`Z*k M VN
hfpSxL
//count++; SrPZ^NF
//if(count>4) -MrEJ
// siteStop(); 0#~e KFy
} H]5%"(h
>}`q4U6$
K~p\B
System.err.println("文件下载结束！"); ENwDW#U9
} ln#Jb&u
catch(Exception e){e.printStackTrace ();} DGMvYNKTj
} %UuV^C
XOQj?Q7)U
VY)!bjW.
//获得文件长度 FWNO/)~t
public long getFileSize() w,(e,8#:
{ )K2,h5zU
int nFileLength = -1; F0O"rN{
try{ <S'5`-&
URL url = new URL(siteInfoBean.getSSiteURL()); EGYYSoBLU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LOf0_g/
httpConnection.setRequestProperty("User-Agent","NetFox"); fS50
9ZjSM,+
`<>Emc8Z
int responseCode=httpConnection.getResponseCode(); u|l]8T9L
if(responseCode>=400) kYwk'\s
{ !ydJ{\;
processErrorCode(responseCode); HE911 lc:
return -2; //-2 represent access is error }~Z1C0t
} 5I,5da
Np>[mNmga
.l$'%AG:~
String sHeader; dALJlRo"
P!qU8AJkt
<^?64
for(int i=1;;i++) [m7^Euury
{ 8<}f:9/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |7Z7_YWs
//Utility.log(in.readLine()); PYDf|S7
sHeader=httpConnection.getHeaderFieldKey(i); 'ojI_%9<
if(sHeader!=null) VkCv`E
{ TY[{)aH{S
if(sHeader.equals("Content-Length")) V_JM@VN}Kk
{ t0XM#9L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); trL:qD+{(
break; UTw f!
} SsiKuoxk
} =}txcA+
else "Gx(-NH+
break; f5jxF"oGNo
} Q70LQCms
} f6x}M9xS%
catch(IOException e){e.printStackTrace ();} ]J\tosTi
catch(Exception e){e.printStackTrace ();} iOI8'`mk
m\~{l=jIS
h~rSM#7m
Utility.log(nFileLength); ydOJ^Yty
j,")c'r&dD
.Cfi/
return nFileLength; n:cre}0.
} $qk2!
2 F3U,}
}ie\-V
//保存下载信息（文件指针位置） zoYw[YP9
private void write_nPos() sqw^Hwy=!2
{ mF\r]ovVm
try{ ]9]cef=h#
output = new DataOutputStream(new FileOutputStream(tmpFile)); Iuk!A?XV
output.writeInt(nStartPos.length); '&{`^l/MH
for(int i=0;i<nStartPos.length;i++) .K>rao'
{ 6XPf0Gl
// output.writeLong(nPos); o@6:|X)7
output.writeLong(fileSplitterFetch.nStartPos); J8[N!qDCj
output.writeLong(fileSplitterFetch.nEndPos); )0Av:eF-+
} 2Uf]qQ1
output.close(); a>jiq8d]4
} B.nq3;Y
catch(IOException e){e.printStackTrace ();} [UN`~
catch(Exception e){e.printStackTrace ();} )N!-g47o%#
} ]Z?$ 5Ks
z>$AZ>t%J$
]F[ V6`H
//读取保存的下载信息（文件指针位置） ;E0Xn-o_
private void read_nPos() \Ub=Wm\
{ 4%do.D*
try{ o.-rdP0P>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ydFZ$W_}w
int nCount = input.readInt(); "|&xUWJ!)
nStartPos = new long[nCount]; 8Qtd,
nEndPos = new long[nCount]; bgs2~50
for(int i=0;i<nStartPos.length;i++) Ym~*5|
{ z7X[$T$V
nStartPos = input.readLong(); _:4n&1{.E
nEndPos = input.readLong(); _&s37A&\
} ni$7)YcF
input.close(); `4E6&&E+S
} ^s<p5V
catch(IOException e){e.printStackTrace ();} ,gHgb
catch(Exception e){e.printStackTrace ();} 7XLz Ewa
} 6@_Vg~=S
?0HPd5=<v
0KknsP7
private void processErrorCode(int nErrorCode) sr(f9Vl
{ 0^htwec!
System.err.println("Error Code : " + nErrorCode); wmu#@Hf/[h
} }lzUl mRTe
.s7Cr0^k,|
sG{hUsPa
//停止文件下载 0mj^Tms
public void siteStop() yeQ6\yi
{ /8 /2#`3R
bStop = true; ptXCM[Z+
for(int i=0;i<nStartPos.length;i++) %G!BbXlz
fileSplitterFetch.splitterStop(); u'"VbW3u n
>W%tEc
#SiOx/
} gKK*` L~
} )sg@HFhY'
//负责部分文件的抓取 NbyVBl0=
**FileSplitterFetch.java cY1d6P0
*/ F.:B_t
package NetFox; {L 7O{:J
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Z~O1$,Z
import java.io.*; Aa^%_5
import java.net.*; '{9nQDgT
1muB* O
9L+dN%C
public class FileSplitterFetch extends Thread { &_cMbFLBP
\ UCOe
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String sURL; //File URL Y>}[c
long nStartPos; //File Snippet Start Position (h;4irfX
long nEndPos; //File Snippet End Position /$v0Rq9
int nThreadID; //Thread's ID `4V_I%lJ&
boolean bDownOver = false; //Downing is over $ K>.|\
boolean bStop = false; //Stop identical Ph(bgQg
FileAccessI fileAccessI = null; //File Access interface %j4
v6B}ov[Y2
Qp9)Rc5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \OMWE/qMy
{ +c@s
this.sURL = sURL; E:,V{&tLK
this.nStartPos = nStart; NEInro<
this.nEndPos = nEnd; S+LE ASOr
nThreadID = id; 1^<R2x
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7Ddo^Gtx
} +z/_'DE
EMyMed_
w#EP`aM2$=
public void run() u*#j;Xc
{ s>8;At-
while(nStartPos < nEndPos && !bStop) |7G+O+j
{ WJ)( *1
cfn\De%.
rv/O^aL`Y
try{ 8 /3`rEW
URL url = new URL(sURL); 58FjzW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X"yjsk
httpConnection.setRequestProperty("User-Agent","NetFox"); 1an?/j,
String sProperty = "bytes="+nStartPos+"-"; JVO,@~~
httpConnection.setRequestProperty("RANGE",sProperty); (<RZZ{m
Utility.log(sProperty); {<XPE:1>Y
iY @MnnX
o/uA_19
InputStream input = httpConnection.getInputStream(); h`X>b/V
//logResponseHead(httpConnection); ;{xk[fm=
rp*f)rJ
,'~8{,h5
byte[] b = new byte[1024]; }%z {tn
int nRead; e.X*x4*>~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9|19ia@[\
{ i}C9
nStartPos += fileAccessI.write(b,0,nRead); hdZ{8 rP
//if(nThreadID == 1) SM3Q29XIw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i|zs Li/
} BJzNh>-#=
e))fbv&V
[d+f#\ut
Utility.log("Thread " + nThreadID + " is over!"); L`v7|!X
bDownOver = true; /Yk4%ZJ{
//nPos = fileAccessI.write (b,0,nRead); Y/\y"a
} Gt9(@USK
catch(Exception e){e.printStackTrace ();} [v7)xV@c
} 5&}~W)"9
} iwJeV J
>l|ao&z>bm
".Lwq_
//打印回应的头信息 F/BB]gUB
public void logResponseHead(HttpURLConnection con) o[C,fh,$
{ }Yd7<"kp
for(int i=1;;i++) ,9T-\)sT
{ /b3b0VfF
String header=con.getHeaderFieldKey(i); <pAN{:
if(header!=null) 3C8cvi[IS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &PJ&XTR
Utility.log(header+" : "+con.getHeaderField(header)); n)]]g3y2
else ')ZM# :G
break; Ja$Ple*XU8
} 6I,^4U
} ^Fmp"[q
_ ^5w f
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public void splitterStop() _T,X z_
{ sxac(L
bStop = true; ,Mt/*^|
} RweK<Flo'S
@9yY`\"ed
xl.iI$P
} I)@b#V=
{*EA5;
# tN#_<W
/* Q>`|{m
**FileAccess.java 8t{-
*//文件访问(定位，写) E_t ^osY&
package NetFox; '`.bmiM
import java.io.*; BT?)-wS
dEz7 @T
KW&5&~)2
public class FileAccessI implements Serializable{ 3vs;ZBM
zq(R!a6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q&p'\6~
RandomAccessFile oSavedFile; 9NX/OctFa'
long nPos; Dwvd
pq<302uBQ
3v oas
public FileAccessI() throws IOException )~((6?k4e
{ xp+Z%0D
this("",0); (`z`ni
} . 4$SNzv3V
5u(B]_r.
Ni"M.O);t
public FileAccessI(String sName,long nPos) throws IOException eVDO]5?
{ "qb1jv#to
oSavedFile = new RandomAccessFile(sName,"rw"); 1y/_D$~ZO
this.nPos = nPos; 3`V#ImV>
oSavedFile.seek(nPos); 5W UM"eBwL
} d(LX;sq?
vjfV??XSU
6gUcoDD
public synchronized int write(byte[] b,int nStart,int nLen) &y164xn'h
{ s\7]"3:wD
int n = -1; UOi[#L@N
try{ y81B3`@
oSavedFile.write(b,nStart,nLen); kZ8+ev=
n = nLen; IaDN[:SX
} "oZ$/ap\
catch(IOException e) /wF*@/PTH
{ )U>JFgpIW
e.printStackTrace (); Ucj eB
} }3{ x G+,
)FF3|dZ";K
S"*M9*8
return n; *U[Nn5#?
} eiiI Wr_7
]yvHb)X
`%PU_;Y5Q
} 4T]n64Yid
VeLuL:4I
6jdNQC$#B
/* 6xFvu7L_c;
**SiteInfoBean.java ?8{x/y:
*/ :E$<!q
package NetFox; %TOYU(k
X`REhvT
@wzzI 7}C
public class SiteInfoBean { u0Nag=cU
H<hFA(M
U{^~X_?
private String sSiteURL; //Site's URL Klw\
private String sFilePath; //Saved File's Path jB"?iC.
private String sFileName; //Saved File's Name 9ZKB,
private int nSplitter; //Count of Splited Downloading File `V(zz
?b}d"QsmU
#n9:8BKf
public SiteInfoBean() .BaU}-5
{//nSplitter的缺省值为5 )Ha`>
//default value of nSplitter is 5 QX1rnVzg0
this("","","",5); dI[hQxU
} , [V#o-Z
%xa.{`}`U
G;^},%<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {$dq7m(
{ tEj-c@`"x-
sSiteURL= sURL; Oa8lrP`(
sFilePath = sPath; >?pWbL
sFileName = sName; ~M>EB6
this.nSplitter = nSpiltter; =\t%U5
m1](f[$
st|;]q9?
} nUgZ]ag=G
9>@@W#TK~
ZmJ!ZKKch
public String getSSiteURL() _8-iO.T+2
{ #u<^
return sSiteURL; ;w\7p a
} 2}NWFM3C
k|Xxr
88K=jo))b
public void setSSiteURL(String value) ?1DA
{ s>pOfXIx
sSiteURL = value; ,3m]jp'
} IvW%n(a8^
LjE@[@d
U\crp T`
public String getSFilePath() aJQx"6c?
{ E3p3DM0F$
return sFilePath; u]D>O$_ s
} Sqc r -
?Aewp$Bj
}qqE2;{ND
public void setSFilePath(String value) Awip qDAu
{ nBVR)|+M
sFilePath = value; l'~~hQ{h/
} j@j%)CCM
E[z8;A^:0
B4/0t:^I
public String getSFileName() ?iX1;c9
{ efK3{
return sFileName; C(ay7
} Lq-Di|6q
a\UhOPFF
$?Et sf#*'
public void setSFileName(String value) YY&3M
{ 3@d{C^\
sFileName = value; !I7bxDzK$
} +PCsp'D d
Usa
eHjna\C
public int getNSplitter() 't3@dz_dG
{ W7j-siWJ
return nSplitter; -T s8y
} &~%( RO
n@hf{hA[a
iva?3.t
public void setNSplitter(int nCount) rO_|_nV[
{ r`; "
nSplitter = nCount; 01/?
} fn!(cE|`E
} 17itC9U
@,Re<%\
r_5k$u(
/* 6I)1[tU
**Utility.java dzK]F/L]
*/ ?r`UBR+[
package NetFox; {3jV ,S
4f}:)M$5
?|&plf|
public class Utility { \Y EV 5
\z/_vzz4
34@f(^d+^
public Utility() fP6]zy^*
{ &oA p[]
,>DaS(
SM<kR1bo
} f9Vxtd
C< :F<[H
//线程睡眠 U%Igj:%?;`
public static void sleep(int nSecond) k:+Bex$g
{ q,<AW>
try{ uv:DO6 {
Thread.sleep(nSecond); <hYrcOt
} $'9b,- e
catch(Exception e) +npcU:(Kg
{ L$ nFRl&
e.printStackTrace (); xnyp'O8yk
} WFOO6 kMz
} Kn#3^>D
# j=r
//日志 K3c(c%$<R
public static void log(String sMsg) Oy @vh>RY
{ =<_ei|ME
System.err.println(sMsg); ~7N>tjB
} \~1>%F'op
CoZXbTq
<2\4eusk
public static void log(int sMsg) LPg1G+e
{ @Ju!|G9z/p
System.err.println(sMsg); m&'z|eN
} ^'g1? F$_
} QQd%V#M?
12NV
~)RKpRga\p
/* 4_#yl9+
**TestMethod.java L@b8,
*/ 91Cg
package NetFox; x8]9Xe:_>O
rC(-dJkV
a]-.@^:_i
public class TestMethod { \2rCT~x
b&Dc DX
jY]hMQ/H
public TestMethod() uq}>5
{ ///xx/weblogic60b2_win.exe oEqt7l[I{
try{ [5v[Zqud
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VW7 ?{EL7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )/'y'd<r
SiteFileFetch fileFetch = new SiteFileFetch(bean); e[3rz%'Q
fileFetch.start(); x*)@:W!
} ~(TS>ck@
catch(Exception e){e.printStackTrace ();} w85PRruW
-PHVM=:
B:YUb{CJ
} lC/4CPKtV
:Kc}R)6
q><E?
public static void main(String[] args) aB`x5vg7ho
{ k)2L<Lmn
new TestMethod(); n9J.]+@J
} y.zS?vv2g
} t=`bXBX1
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