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=]5WZO~A
} ~LQ[4h<J !
for(int i=0;i<nEndPos.length-1;i++) ; "3+YTtp
{ ~np,_yI
nEndPos = nStartPos[i+1]; ^S#t|rN
} G9g6.8*&
nEndPos[nEndPos.length-1] = nFileLength; oK9'
} Yct5V,X^
} gf)t)-E
j6ut}Uq
B%\gkl
//启动子线程 5HS~op2n/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q*)+K9LRk
for(int i=0;i<nStartPos.length;i++) W9zE{)Sc~
{ iK_c.b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jg$xO@.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ei({`^
nStartPos,nEndPos,i); 23DJV);g8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s0hBbL0DH
fileSplitterFetch.start(); ;o<m}bGaT
} N{d@^Yj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6*@yE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Vga-@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2yo cu!4l
nEndPos = " + nFileLength); (ozb%a#B
// fileSplitterFetch[nPos.length-1].start(); O3NWXe<
[t0rfl{.
;pRcVL_4
//等待子线程结束 T{vR,
//int count = 0; )$x_!=@1
//是否结束while循环 $(q>mg:H
boolean breakWhile = false; SJgY
hF&}lPVtv
P(omfD4
while(!bStop) (!?K7<Jv
{ xU9@$am
write_nPos(); H]#Rg`~n
Utility.sleep(500); 5c-N0@\
breakWhile = true; mW`oq
g2p"LWex-
+K6szGP
for(int i=0;i<nStartPos.length;i++) #NRh\Wj|
{ dX )W0
if(!fileSplitterFetch.bDownOver) XT@Mzo49z\
{ '7Ig.K&
breakWhile = false; }{],GHCjQ
break; >E"9*:.^a
} u2sR.%2U<
} d @rs3Q1z
if(breakWhile) t"s5\;IJ
break; k<4P6?
19d6]pJ5
`Xo4q3
//count++; $(HjI \%l^
//if(count>4) ?$%%Mp(
// siteStop(); 3 EYiQ`
} yqSY9EX7
gX} g
5^)_B;.f
System.err.println("文件下载结束！"); ^lO76Dz~a
} (B`sQw@tu
catch(Exception e){e.printStackTrace ();} Qu~*46?0
} 2Ji+{,?,
E(L<L1:"
Ttv9"z
//获得文件长度 ;rBp1[qVe
public long getFileSize() +2T!z=
{ WtX>Qu|
int nFileLength = -1; ]HvZ$
try{ [6gO
URL url = new URL(siteInfoBean.getSSiteURL()); r[HT9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w+f=RHX"{
httpConnection.setRequestProperty("User-Agent","NetFox"); O]nT>;PXX
QD<eQsvV
jQtSwVDr
int responseCode=httpConnection.getResponseCode(); ,{<p
if(responseCode>=400) d\]O'U)s
{ y@apJ;_R-
processErrorCode(responseCode); v:d9o.h
return -2; //-2 represent access is error Q~ 0Dfow?
} Gq]d:-7l
]h~o],:
`Q9+k<
String sHeader; g#W_S?
T{-2fp8r[
3eg5oAZ)G8
for(int i=1;;i++) W^xZ+]
{ |f NMs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |Cf mcz(56
//Utility.log(in.readLine()); {j6g@Vd6lx
sHeader=httpConnection.getHeaderFieldKey(i); -i_En^Fi
if(sHeader!=null) IL2r9x%
{ lfy7w|
if(sHeader.equals("Content-Length")) AQ@v>wr}
{ NfF~dK|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); koH4~m{
break; d=e{]MG(
} .C5@QKU
} T"W9YpZ
else ~Fx&)kegTo
break; iVeQ]k(u
} 4r*Pa(;y
} 6ojo##j
catch(IOException e){e.printStackTrace ();} W/v|8-gcK
catch(Exception e){e.printStackTrace ();} `s}BXKIv}
"T*I|
#?m{YT{P
Utility.log(nFileLength); -2lRia
wD=am
R{<Y4C2~
return nFileLength; BLW]|p|1:
} %c1FwAC
z~.9@[LG]
FaWl,}]
//保存下载信息（文件指针位置） 37KU~9-A
private void write_nPos() cV]y=q6
{ 7!- \L7<
try{ ^K*-G@B
output = new DataOutputStream(new FileOutputStream(tmpFile)); _$(GRNRYK
output.writeInt(nStartPos.length); ylkqhs&
for(int i=0;i<nStartPos.length;i++) :r39wFi
{ I*c;hfu
// output.writeLong(nPos); BkT-m'I?
output.writeLong(fileSplitterFetch.nStartPos); n2E4!L|q
output.writeLong(fileSplitterFetch.nEndPos); MF|*AB|E
} a4u^f5)@
output.close(); s]bPV,"p
} #PH#2/[
catch(IOException e){e.printStackTrace ();} ]BfR.,,
catch(Exception e){e.printStackTrace ();} T?e9eYwS
} b_ JWnh
I{<;;;a
<_f`$z
//读取保存的下载信息（文件指针位置） vXf:~G]
private void read_nPos() (txt8q
{ 08io<c,L
try{ *+~D+_,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^;64!BaK
int nCount = input.readInt(); ;o%:7&
nStartPos = new long[nCount]; IQoH@l&Xk
nEndPos = new long[nCount]; #Gp M22d'(
for(int i=0;i<nStartPos.length;i++) TF)8qHy! u
{ Zsk?QS FE
nStartPos = input.readLong(); =~$U^IsWA
nEndPos = input.readLong(); /h-6CR Ka
} tGqQJT#mr7
input.close(); (uT^Nn9L=
} 4ac1m,Jlt
catch(IOException e){e.printStackTrace ();} ^yD"d =z
catch(Exception e){e.printStackTrace ();} &vkp?UH
} zP|*(*
lrn+d$!@
{]@Qu"M
private void processErrorCode(int nErrorCode) -3`Isv
{ &%}6q]e
System.err.println("Error Code : " + nErrorCode); X?kPi&ru
} 1!f2*m
xiJz`KD&
V^ Y*xZ
//停止文件下载 [>wzl"cHW
public void siteStop() Pzptr%{
{ W60Q3
bStop = true; cb4b,Ri
for(int i=0;i<nStartPos.length;i++) 1{7_ `[
fileSplitterFetch.splitterStop(); =<>pKQ)[
wmiafBA e
s79q5
} >&[3
} Q~h6J*
//负责部分文件的抓取 i&1U4q
**FileSplitterFetch.java _&K\D p&@
*/ gTuX *7w
package NetFox; XX:q|?6_ 4
UCn.t
5{HtJ?sKc5
import java.io.*; UXQb={
import java.net.*; }`4K)(>4nG
,NDxFy;d
!rz)bd3$
public class FileSplitterFetch extends Thread { *seu&
H}(=?}+
< )Alb\Z
String sURL; //File URL 6l<1A$BQ
long nStartPos; //File Snippet Start Position I=K[SY,]9
long nEndPos; //File Snippet End Position 4%%B0[Wo_O
int nThreadID; //Thread's ID OAY8,C=M
boolean bDownOver = false; //Downing is over oAC^4-Ld
boolean bStop = false; //Stop identical TXx'7[
FileAccessI fileAccessI = null; //File Access interface v=j>^FZ
G u6[{u
*|sxa#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ujow?$&
{ B6(h7~0(<
this.sURL = sURL; v<%]XHN
this.nStartPos = nStart; XEa~)i{O
this.nEndPos = nEnd; \N4d_fPj
nThreadID = id; `)LIVi"(D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /XjN%|
} 7<fL[2-
mQFa/7FX
:mzCeX8 *
public void run() Cv0&prt
{ QZ?O;K1|y
while(nStartPos < nEndPos && !bStop) '+tKvTU;
{ HqB|SWyK
VVgsLQd
Ko@zk<~"[
try{ oEN)Dw o
URL url = new URL(sURL); `3]Rg0g&Xe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tx gvVQ
httpConnection.setRequestProperty("User-Agent","NetFox"); NYGmLbq
String sProperty = "bytes="+nStartPos+"-"; u0wn=Dg
httpConnection.setRequestProperty("RANGE",sProperty); Jk%'mEGE
Utility.log(sProperty); (21']x
o; 6fvn
~v^%ze
InputStream input = httpConnection.getInputStream(); Ri9Kr
//logResponseHead(httpConnection); :EYu 4Y
56"#Syj
/*AJ+K._
byte[] b = new byte[1024]; poTl|y @
int nRead; bkxk i@t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4t,zHR6W
{ oo;;y,`8py
nStartPos += fileAccessI.write(b,0,nRead); IkiQOk
//if(nThreadID == 1) c6f|y_2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @< wYT$
} xq#U4E
<'yf|N!9G
"[#@;{@Gt
Utility.log("Thread " + nThreadID + " is over!"); \FIa,5k8
bDownOver = true; Gv!BB=ir(
//nPos = fileAccessI.write (b,0,nRead); #4Dn@Gqh.Y
} |if~i;VKL
catch(Exception e){e.printStackTrace ();} Y]hV-_2+Do
} bl$+8!~
} N[#iT&@T}/
pk;ffq@
kA;xAb+U3
//打印回应的头信息 \8=e|a5`
public void logResponseHead(HttpURLConnection con) y;zt_O/
{ ,:Rft
for(int i=1;;i++) w906aV*s
{ tZdwy>;
String header=con.getHeaderFieldKey(i); A*G )CG
if(header!=null) oNiToFbQu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JZWgr&O<
Utility.log(header+" : "+con.getHeaderField(header)); (y-x01H
else <WZ1-
break; -q'xC:m
} i7i|370
} #;wkr))
Uzan7A
/'R UA
public void splitterStop() DZ%g^DRZX
{ LvSP #$f
bStop = true; aQl?d<|+lk
} MZ;"J82p
,Wz[tYL*
[?Mc4uT{
} C/{nr-V3u
*p""YEN
`G_(xN7O
/* CPc"
**FileAccess.java ,`ZPtnH+
*//文件访问(定位，写) X_vI0YX9
package NetFox; 3*CzXK>`M&
import java.io.*; +A]&AkTw
Z}sG3p
B rez&3[
public class FileAccessI implements Serializable{ 8O"x;3I9
kHt!S9r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &:;/]cwj
RandomAccessFile oSavedFile; u@GRN`yn
long nPos; nQ:ml
*,O :>Z5I
+O;OSZ
public FileAccessI() throws IOException X{0ax.
{ se<i5JsSV
this("",0); =fKhXd
} Hv[d<ylO
7V9%)%=h|
nu\
public FileAccessI(String sName,long nPos) throws IOException wJapGc!
{ GVjv**U
oSavedFile = new RandomAccessFile(sName,"rw"); D=i0e8D!+
this.nPos = nPos; s[0prm5.
oSavedFile.seek(nPos); G;PbTsW
} {{^Mr)]5K
Ma`
aHBByH
public synchronized int write(byte[] b,int nStart,int nLen) }V1DyLg:
{ K$Mx}m7l
int n = -1; 3EbnZb
try{ [(D}%+2
oSavedFile.write(b,nStart,nLen); NZfo`iHAN
n = nLen; a}5vY
} O0K@M
catch(IOException e) H]%mP|
{ iFAoAw(
e.printStackTrace (); 377j3dP
} \j,v/C@c-
0Zc*YdH
adRNrt*!
return n; r6O7&Me<
} '<RB
V\iIvBpWg
q;1VF;<"vH
} oiTMP`Y
)z?&"I
~|aeKtCs(.
/* USnD7I/b
**SiteInfoBean.java `@u+u0
*/ /o<}]]YBF
package NetFox; ,wry u|7"$
7|h3.
>.!5M L\
public class SiteInfoBean { .d#G]8suF
H3p4,Y}'#
+P> A P&
private String sSiteURL; //Site's URL X]+(c_i:hC
private String sFilePath; //Saved File's Path *sc0,'0
private String sFileName; //Saved File's Name wzNt c)~i
private int nSplitter; //Count of Splited Downloading File bMK#^ZoH
=\ti<
"6I-]:K-
public SiteInfoBean() P-E'cb%ub
{//nSplitter的缺省值为5 h-?q6O/|
//default value of nSplitter is 5 0I(GB;E
this("","","",5); (/9.+V_
} aIn)']
4y]:Gqz~
'b=eC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <tu[cA>
{ Z3X&<Y5
sSiteURL= sURL; /JK-}E
sFilePath = sPath; /VhE<}OtH
sFileName = sName; ;EE&~&*w
this.nSplitter = nSpiltter; fwnYzd3
dCoi>PO
^B&ahk
} ^ RcIE (
ery?G-
ZZ]OR;8
public String getSSiteURL() @MlU!oR&
{ <WHs
return sSiteURL; "a0u-}/D
} SBN_>;$c5}
f}9PEpa,Z
H/^TXqQ8
public void setSSiteURL(String value) lH,]ZA./
{ XoH[MJC
sSiteURL = value; *Lb(urf
} 0?5%
Fl#VKU3h
n&3iv^
public String getSFilePath() Gw\G+T?M-
{ 'sjJSc
return sFilePath; =7J|KoKK
} :C|>y4U&(s
g'}`FvADi
@T,H.#bL
public void setSFilePath(String value) 7fN&Q~.
{ #g-*n@ 1
sFilePath = value; L?D~~Jb
} iZkW+5(
~-`BSR
`%mBu`A
public String getSFileName() X#Dhk6
{ ?,i#B'Z^
return sFileName; vS J<
} Z68Wf5@to&
9 .&Or4>
:,}:c%-^"
public void setSFileName(String value) ]UCk_zWsn1
{ ik1L
sFileName = value; R.2KYhp,
} rmg";(I
k^dCX+
?{.b9`
public int getNSplitter() 8x^H<y=O
{ mtWx ?x
return nSplitter; 7QOC]:r
} |bG[TOa
Y;> p)'z
g]@R'2:1
public void setNSplitter(int nCount) Cs1%g
{ Nz>E#.++
nSplitter = nCount; a`@<ZsR
} jB/q1vFO
} vRb(eg
E/L?D
M#lVPXS
/* 5rHnU<H@y
**Utility.java &J&w4"0N'
*/ '/yx_RK2?
package NetFox; $Op/5j
eFXi )tl
HDW\S#
public class Utility { 1:;&wf
LnRi+n[@7
A]SB c2
public Utility() !7NzW7j
{ t1RwB23
8#Z\}gGz
%dk$K!5D0
} "za*$DU
MlC-Aad(
//线程睡眠 K`_E>k
public static void sleep(int nSecond) gH{\y5%rO
{ [>Kxm
try{ zk 'e6
Thread.sleep(nSecond); 4qSS<SqY
} qYu!:xa8
catch(Exception e) C@?e`=9(
{ %`T^qh_dE
e.printStackTrace (); h&)vdCCk
} :jKXKY+T
} #u=O 5%.
M4hN#0("4
//日志 %CE@}
public static void log(String sMsg) o2e h)rtB
{ Ko]h r
System.err.println(sMsg); EPd.atA
} U5ud?z()OA
f s"V'E2a
p_40V%y^
public static void log(int sMsg) ;k41+O:f@
{ _]r)6RT
System.err.println(sMsg); %"KWjwp
} (zLIv9$
} q!oZ; $
CD<u@l,1
g-V\s&}
/* dBq,O%$oq
**TestMethod.java h9n<ped`A;
*/ ?L#SnnE
package NetFox; 1yRd10
l;VGJMPi
(b2^d
public class TestMethod { pu)9"Ad[ G
l<K.!z<-:8
h}%M
public TestMethod() MVL }[J
{ ///xx/weblogic60b2_win.exe c%3 @J+z
try{ "vRqtEBO@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G-i_s6Wu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nu9k{owB T
SiteFileFetch fileFetch = new SiteFileFetch(bean); e4W];7_K!
fileFetch.start(); -I-&<+7v
} .W+4sax:
catch(Exception e){e.printStackTrace ();} i K[8At"Xo
Di1G
vls> 6h
} [c!vsh]^
iIEIGQx
YK+Z0ry
public static void main(String[] args) .6/p4OR|
{ |2&mvjk@H
new TestMethod(); gLxyRbVI
} hE#8_34%s
} %Kfa|&'zV
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