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)); [<yUq zm
} =|^W]2W$
for(int i=0;i<nEndPos.length-1;i++) B3=/iOb#
{ lY8Qy2k|
nEndPos = nStartPos[i+1]; MZ[g|o!)v
} w'j]Y%
nEndPos[nEndPos.length-1] = nFileLength; [?(W7
} ziip*<a!_
} AZP>\Dq
P =Gb
zTzG&B-
//启动子线程 h*'5h!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q^;\!$:M
for(int i=0;i<nStartPos.length;i++) */qc%!YV9
{ '4S@:.D`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?-p aM5Q+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "K=)J'/n
nStartPos,nEndPos,i); bpCe&*\6K
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z@Z`8M@Q,
fileSplitterFetch.start(); 6:X\vw
} iC\=U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lJ2/xE]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S;kc{?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KAaeaiD
nEndPos = " + nFileLength); `qEm5+`
// fileSplitterFetch[nPos.length-1].start(); DEuW'.o>
m$j;FKz+|
ImW~Jy
//等待子线程结束 UeTp,
//int count = 0; ?=Qg
//是否结束while循环 -B! TA0=oJ
boolean breakWhile = false; k18V4ATE]
vK/Z9wR*05
U5s]dUs (
while(!bStop) 'GT`%ck
{ CawVC*b3
write_nPos(); X~b+LG/
Utility.sleep(500); 8hV:bz"
breakWhile = true; ZPog)d@!
tV%\Jk),
k}7)pJNj
for(int i=0;i<nStartPos.length;i++) NV~i4R*#
{ B*Xh$R
if(!fileSplitterFetch.bDownOver) QR8Q10
{ %^A++Z$`
breakWhile = false; qa#F}aGd
break; ^DJU99
} T!$HVHh&,}
} 2?&ptN)`N
if(breakWhile) `84yGXLK
break; x$4'a~E
=i<(hgD
)^3655mb
//count++; o*8 pM`uw
//if(count>4) W{2y*yqY
// siteStop(); l;i u`
} breVTY7 S
DSa92:M}
fR{7780WZ
System.err.println("文件下载结束！"); s_$@N!
} VNfx>&`
catch(Exception e){e.printStackTrace ();} }7^*%$
} jR:Fih-}
(CwaOm{g
6FAP *V;
//获得文件长度 /zAx`H
public long getFileSize() \|s/_35(
{ Wb$bCR#?<
int nFileLength = -1; `UPmr50Wq
try{ ;#
URL url = new URL(siteInfoBean.getSSiteURL()); B 8,{jwB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ObnB6ShKi
httpConnection.setRequestProperty("User-Agent","NetFox"); \`&fr+x
A 2 )%+
~d]7 Cl
int responseCode=httpConnection.getResponseCode(); ^|z>NV5>
if(responseCode>=400) Ac%K+Pgk.
{ ~KvCb3~X
processErrorCode(responseCode); $'wl{D"
return -2; //-2 represent access is error 7 |A,GH
} y+<HS]vyV
(d\bSo$]
Vh&KfYY
String sHeader; \v_(*
A5\S0l$Q
igCtq!.a
for(int i=1;;i++) %kT:"j(xW
{ pDT6>2t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |\ L2q/u
//Utility.log(in.readLine()); j=LF1dG"
sHeader=httpConnection.getHeaderFieldKey(i); R8)"M(u=l
if(sHeader!=null) BGS6uV4^>
{ ~b/>TKn+
if(sHeader.equals("Content-Length")) ;2~Q97c0
{ ;DpK*A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x~.U,,1
break; -W,b*U
} ~heF0C_
} bzS [X
else _BV:i:z
break; YXEZ&$e'
} jXQ_7
} Q)/q h;Ru
catch(IOException e){e.printStackTrace ();} i)ctrdP-
catch(Exception e){e.printStackTrace ();} =r2d{
?auiq
-mF9Skj
Utility.log(nFileLength); mBF?+/l
&3efJ?8
|SmN.*&(9
return nFileLength; U;/ )V
} @AFLFX]
D.~t#a A
*W l{2&
//保存下载信息（文件指针位置） g& Rk}/F
private void write_nPos() fi)ypv*
{ Et(prmH
try{ DDEn63{
output = new DataOutputStream(new FileOutputStream(tmpFile)); O(VV-n7U
output.writeInt(nStartPos.length); jn'8F$GU
for(int i=0;i<nStartPos.length;i++) z&8#1'
{ ?.H*!u+9>
// output.writeLong(nPos); j(rFORT
output.writeLong(fileSplitterFetch.nStartPos); ~F-,Q_|-
output.writeLong(fileSplitterFetch.nEndPos); >JhQ=j
} %WR
output.close(); - U|4`{PP
} s]qfLC
catch(IOException e){e.printStackTrace ();} FpEdwzBb<
catch(Exception e){e.printStackTrace ();} ur|2FS7
} TBzM~y
FVHL;J]nf1
)Z#7%,o
//读取保存的下载信息（文件指针位置） ,3K?=e2
private void read_nPos() AWzpk}\
{ :c>,=FUT
try{ M:~#"lfK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]KmYPrCl0
int nCount = input.readInt(); B4?P"|
nStartPos = new long[nCount]; K"D9.%7
nEndPos = new long[nCount]; >_o_&;=`v
for(int i=0;i<nStartPos.length;i++) Kt-@a%O0
{ <Aa%Uwpc
nStartPos = input.readLong(); Je'$V%{E
nEndPos = input.readLong(); KK?}`o
} ?$?Ni)Z
input.close(); 4d#W[
} "](~VF[J8
catch(IOException e){e.printStackTrace ();} XxGm,A+>Ty
catch(Exception e){e.printStackTrace ();} bFpwq#PDW>
} A6d+RAx
\,WPFV
GM5::M]fS
private void processErrorCode(int nErrorCode) mxIEg?r(
{ ci!c7 ,'c
System.err.println("Error Code : " + nErrorCode); <D__17W:;
} 1~+w7Ar=(
5)vXmAD/0
jH8F^KJM[
//停止文件下载 >,[(icyzn
public void siteStop() <(v!Xj^yO
{ +$%o#~
bStop = true; 8ViDh
for(int i=0;i<nStartPos.length;i++) "}n]0 >J
fileSplitterFetch.splitterStop(); ]k hY8it
V\ |b#?KL
09Fr1PL
} 7-^d4P+|g
} |Bjb
//负责部分文件的抓取 gG}<l ':
**FileSplitterFetch.java 0@ -LV:jU
*/ 8WAg{lVs
package NetFox; M*x_1h5n
<v\|@@X
*StJ5c_kg2
import java.io.*; lHx$F?
import java.net.*; 8?PNyO-Wt5
gw H6r3=y(
fE(rDQI
public class FileSplitterFetch extends Thread { 4 1Ru@
<_D+'[
j,~h:MT
String sURL; //File URL %l>^q`p
long nStartPos; //File Snippet Start Position D~-Ri`k.
long nEndPos; //File Snippet End Position p%}oo#%J
int nThreadID; //Thread's ID ZY83,:<
boolean bDownOver = false; //Downing is over *_ "j"{
boolean bStop = false; //Stop identical pvX\kX3}
FileAccessI fileAccessI = null; //File Access interface $zJ.4NA
)msqt!Ev
:5ji.g* 0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q@2Smtu~c
{ x{=ty*E
this.sURL = sURL; +;vfn>^!b
this.nStartPos = nStart; /V,:gLpQ
this.nEndPos = nEnd; 7y:J@fh<
nThreadID = id; 5[0n'uH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wL:3RZB
} 8^O|Aa$IF:
4h-y'&Z
Gv<K#@9T
public void run() E0GpoG5C
{ mX %;
while(nStartPos < nEndPos && !bStop) _Ab|<!a/R
{ C,Ch6Ph
_KKG^ u<
*dGW=aM#C
try{ ,9=a(j"
URL url = new URL(sURL); R#oXQaBJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8NpQ"0X
httpConnection.setRequestProperty("User-Agent","NetFox"); :=-h'<D
String sProperty = "bytes="+nStartPos+"-"; }v`5
httpConnection.setRequestProperty("RANGE",sProperty); 'peFT[1>(
Utility.log(sProperty); Yk:\oM
4\t9(_
ZMbv1*Vt
InputStream input = httpConnection.getInputStream(); 9=:!XkT.
//logResponseHead(httpConnection); v-OaH81&R
D{c`H}/`
6%:N^B=%}
byte[] b = new byte[1024]; n:HF&j4C,
int nRead; gQ&FO~cr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w!h!%r
{ [$B
nStartPos += fileAccessI.write(b,0,nRead); @zE_fL
//if(nThreadID == 1) CB|Z~_Bm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gVA$P
} KN5.2pp
[}.OlR3)
]GRPxh
Utility.log("Thread " + nThreadID + " is over!"); QH;1*
bDownOver = true; ;|66AIwDe
//nPos = fileAccessI.write (b,0,nRead); 68d(6?OgW
} $6R<)]6
catch(Exception e){e.printStackTrace ();} |NL$? %I
} XBCz\f
} \ 3ha
{,,w5/k^
6:@tHUm
//打印回应的头信息 f~9ADb
public void logResponseHead(HttpURLConnection con) @va6,^)
{ 7|*|xLrVY
for(int i=1;;i++) rT <=`9^{
{ c/b}39X
String header=con.getHeaderFieldKey(i); BJ1txdxvS
if(header!=null) ^,@Rd\q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AS~O*(po
Utility.log(header+" : "+con.getHeaderField(header)); H+t^eg88
else "|(+~8[
break; n hS=t8H
} ur"ckuG!9
} d.sxB}_O
C}%g(YRhb
^~?VD
public void splitterStop() v:eVK!O
{ B]#0]-ua
bStop = true; cW%F%:b
} 0OP6VZ\
VQ2)qJ#l
weKwBw
} .(ki(8Z N
~}(}:#>T
M{Wla7
/* nTyKZ(#u
**FileAccess.java Od)]FvO
*//文件访问(定位，写) )Yy`$`
package NetFox; ohOze\T)=
import java.io.*; Kb#py6
Syo1Dq6z.
R=xT\i{4h
public class FileAccessI implements Serializable{ S!0<aFh
==~X8k|{E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9H`Q |7g(5
RandomAccessFile oSavedFile; gM '_1zs U
long nPos; [YLaRr
+<(N]w*
D`V03}\-
public FileAccessI() throws IOException k& 2U&
{ -$>R;L
this("",0); LY-fp+
} ?l &S:` L
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IR(qjm\V
public FileAccessI(String sName,long nPos) throws IOException Lp.,:z7
{ $<OX\f%
oSavedFile = new RandomAccessFile(sName,"rw"); GFB(c
this.nPos = nPos; :D""c*
oSavedFile.seek(nPos); i]JD::P_H
} c=0S]_
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Ivmiz{Oii
public synchronized int write(byte[] b,int nStart,int nLen) lQ {k
{ oYG9i=lZ
int n = -1; KY~p>Jmh
try{ TmxhP nJ~
oSavedFile.write(b,nStart,nLen); qH1[BsOx
n = nLen; 4$oNh)+/h
} 40w,:$
catch(IOException e) N7v7b<6
{ Tu"bbc
e.printStackTrace (); &!SdO<agZ
} p8aGM-+40W
<%Zg;]2H`
_Ryt|# y
return n; c|.~f+
} -~n^?0
{N42z0c
&`Oj<UyJY
} >4b:`L
G:7HL5u
c07'mgsU
/* _bRd2k,
**SiteInfoBean.java DO` K_B
*/ ?%-VSL>$w=
package NetFox; Up*1j:_O
ND $m|V-C
I|8'#QX
public class SiteInfoBean { 0}tf*M+a
_4Z|O]
va 7I_J
private String sSiteURL; //Site's URL 33IJbg
private String sFilePath; //Saved File's Path -}#=L@
private String sFileName; //Saved File's Name \]uD"Jqv#
private int nSplitter; //Count of Splited Downloading File JcV'O)&
BPs|qb-
jGy%O3/
public SiteInfoBean() R-QSv$
{//nSplitter的缺省值为5 V{4=,Ax
//default value of nSplitter is 5 I8~ .Vu2
this("","","",5); g^ .g9"
} @`t#Bi9
&.^(,pt
5ar2Y$bY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qf|x]x*5
{ !8YZ;l
sSiteURL= sURL; k@:M#?(F
sFilePath = sPath; Bu_/yKW
sFileName = sName; y.vYT{^
this.nSplitter = nSpiltter; M~/7thP{
R<(kiD\?]
{;mT.[
} t7#lRp&
R. :~e
$.HZz
public String getSSiteURL() ,'!x9 `
{ Rn?Yz^ 1q
return sSiteURL; 3lr9nBR
} \"k[y+O],4
I "Qf};n
|p_\pa1&
public void setSSiteURL(String value) ^V6cx2M
{ 76 nrDE
sSiteURL = value; \EI<1B
} J34/rL/s
/Q]6"nY
}OZut!_
public String getSFilePath() l/*NscYtQ
{ 6="Qwrk
return sFilePath; 0SS,fs<w3
} vX?MB
Lsu_f'p0
>%6a$r~@
public void setSFilePath(String value) ]cQYSN7!SY
{ ({&\~"
sFilePath = value; Y6W#uiqk
} JJC YM
xD.Uh}:J
+|0f7RB+R
public String getSFileName() IkWV|E
{ oyw*Z_9~
return sFileName; a%nksuP3
} =:fN
U~3uu&/r
1PGY/c
public void setSFileName(String value) 5z/*/F=X
{ ,i]X^z5!
sFileName = value; I}^Q u0ub
} r,cz yE/
`|uwR5
;D8175px;
public int getNSplitter() &[yW}uV<7
{ vM3 b\yp
return nSplitter; zjE|UK{
} v79k{<Ln
S[zETRSG
2.p?gRO
public void setNSplitter(int nCount) n3z]&J5fr
{ Z-U-n/6I
nSplitter = nCount; wn1` 9
} qX9x#92
} L.ML0H-
Nh^ lC
4 *n4P
/* gI T3A*x
**Utility.java ;6)Onwx
*/ r+RFDg/
package NetFox; KT3n-Y-,
QH5[}zs8
y|b&Rup
public class Utility { HpKF7oJ'N
7jS`4,
HuI?kLfj\
public Utility() UwtLvd
{ 5mqwNAv
'g5 Gdn
UG !+&ii|
} 90Sp(
0FAe5 BE7
//线程睡眠 9 $&$Fe
public static void sleep(int nSecond) [,a2A
{ dy' J~Eo7
try{ O~*`YsL9
Thread.sleep(nSecond); P->.eo#VG
} hU|TP3*
catch(Exception e) bC h
{ Pd8zdzf{
e.printStackTrace (); Cs2F/M'
} |Y tZOQu
} Lk8[fFa4
h uIvXl
//日志 vT=?UTq
public static void log(String sMsg) 9aoGptgN
{ h_y;NB(w
System.err.println(sMsg); $S'~UbmYU
} ~PZIYG"D
AZH=r S`
]EWEW*'j
public static void log(int sMsg) U(6=;+q
{ I xk+y?
System.err.println(sMsg); *Dhy a g
} o+0x1Ct3P
} (#Ku`
$8{v_2C){
y[A%EMd
/* Q!ReA{
**TestMethod.java o6ag{Yp
*/ wa%;'M&
package NetFox; AuIg=-xR
)`,Y^`F2
=\FV_4)
public class TestMethod { D.ERt)l>
+:ih`q][b
G~X93J
public TestMethod() _I/uW|>
{ ///xx/weblogic60b2_win.exe [XbNZ6
try{ %8c2d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M"\j7(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W[SZZV_(tu
SiteFileFetch fileFetch = new SiteFileFetch(bean); #V-0-n,`
fileFetch.start(); B,(zp#&yB
} S{fFpe-
catch(Exception e){e.printStackTrace ();} c( 8>|^M
0[In5II
61pJVOe
} _Squ%z:D
b-OniMq~
GX#SCZ&}C
public static void main(String[] args) y!u=]BE
{ *LOUf7`
new TestMethod(); 1+ib(MJ<:#
} hM "6-60
} AI,Jy%62/
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