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)); +l42Awl>K
} .S EdY:
for(int i=0;i<nEndPos.length-1;i++) V_)-#=J
{ ),_@WW;k
nEndPos = nStartPos[i+1]; uIY#e<)}G
} n5|fHk^s
nEndPos[nEndPos.length-1] = nFileLength; ]|#+zx|/D
} "BAK !N$9
} g9OY<w5s]
BqEI(c6
r[e##M
//启动子线程 (xycJ`N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?C]vS_jAh
for(int i=0;i<nStartPos.length;i++) 6dHOf,zjm
{ pG_;$8Hc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k``_EiV4t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pt?bWyKG
nStartPos,nEndPos,i); R- X5K-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]43/`FX
fileSplitterFetch.start(); L]7=?vN=8
} />C^WQI^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +8T?{K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "%)qRe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \Zk;ikEY
nEndPos = " + nFileLength); cUk7i`M;6
// fileSplitterFetch[nPos.length-1].start(); `Uq#W+r,
D#aDv0b
b\f O8{k
//等待子线程结束 #x@$lc=k3
//int count = 0; oueC
//是否结束while循环 ]dVGUG8
boolean breakWhile = false; 4>YR{
]U?^hZ_
<(#(hDwy
while(!bStop) 0J*??g-n
{ *YI98
write_nPos(); yHYsZ,GE
Utility.sleep(500); . P viA
breakWhile = true; I]|Pq
oE@a'*.\
;T\%|O=Ke
for(int i=0;i<nStartPos.length;i++) OHN_
{ RIR\']WN
if(!fileSplitterFetch.bDownOver) _1X!EH"
{ q$L%36u~/
breakWhile = false; '$Dn
break; 2B1q*`6R
} P.se'z)E
} 85= )lu
if(breakWhile) rCEyQ)R_}
break; !"AvY y9
m~BAyk^jo3
TJd)K$O>
//count++; Xxj- 6i
//if(count>4) 8bGd} (
// siteStop(); %X]jaX7
} thh.A
R>|{N9
Ng&%o
System.err.println("文件下载结束！"); ejKucEgD
} ,i NXK
catch(Exception e){e.printStackTrace ();} @)F)S7
} eSn+B;
Vsr.=Nd=
5PCqYN(:B
//获得文件长度 `?H]h"{7Q
public long getFileSize() -]Bq|qTH[(
{ (M|Dx\_
int nFileLength = -1; =HK!(C
try{ zC:ASt
URL url = new URL(siteInfoBean.getSSiteURL()); b)#hSjWO#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -:^U_FL8un
httpConnection.setRequestProperty("User-Agent","NetFox"); n)/z0n!\
ZmqKQO
QpH'PYy
int responseCode=httpConnection.getResponseCode(); W-f=]eWg
if(responseCode>=400) Z3e| UAif
{ uh_RGM&
processErrorCode(responseCode); *tFHM &a
return -2; //-2 represent access is error C.:<-xo
} u]wZQl#-
.8g)av+
~%F9%=
String sHeader; !.$I["/=
9)yJ: N#F
.~db4d]
for(int i=1;;i++) KM0ru
{ L<S9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wo}H'Q}Hj
//Utility.log(in.readLine()); }v;V=%N+v
sHeader=httpConnection.getHeaderFieldKey(i); ~Gp[_ %K
if(sHeader!=null) yf)%%&
{ UXz<)RvB
if(sHeader.equals("Content-Length")) Mexk~zA^
{ ;a!S!%.h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); P{`C^W$J^
break; M7\szv\Zc=
} fm%t^)E
} A|[?#S((]
else @u+]aI!`-
break; FZQP%]FX
} r r %V.r;2
} G>_*djUf
catch(IOException e){e.printStackTrace ();} 2szPAuN+
catch(Exception e){e.printStackTrace ();} lBE=(A`
H'5)UX@LP
eIF5ZPSZi
Utility.log(nFileLength); "!P3R1;%
%`r$g[<G
5pG}Yk_(x
return nFileLength; tFn)aa~L
} n80?N}
JG.y,<xW
gaxsv[W>^
//保存下载信息（文件指针位置） +^ac'Y)A
private void write_nPos() P:S.~Jq
{ A 'be8
try{ @s&71a
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q}JOU
output.writeInt(nStartPos.length); 2W(s(-hD
for(int i=0;i<nStartPos.length;i++) m 0C@G5
{ X05/uX{
// output.writeLong(nPos); h&iC;yj=
output.writeLong(fileSplitterFetch.nStartPos); P5V}#;v
output.writeLong(fileSplitterFetch.nEndPos); 6wRd<]C
} K3&qq[8.e
output.close(); s[*rzoA
} #zy:a%
catch(IOException e){e.printStackTrace ();} Es`Px_k
catch(Exception e){e.printStackTrace ();} Wb_J(!da
} ~_)^X
@;4zrzQi7
<}Vrl`?h
//读取保存的下载信息（文件指针位置） 7+cO_3AB
private void read_nPos() C&f= ywi0
{ s^TZXCyF o
try{ Wi<m{.%\E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =s{>Fsm1
int nCount = input.readInt(); AN m d!
nStartPos = new long[nCount]; >uB?rGcM
nEndPos = new long[nCount]; CW K7wZM
for(int i=0;i<nStartPos.length;i++) P;no?
{ Q*cf(
nStartPos = input.readLong(); 2.y-48Nz
nEndPos = input.readLong(); dQX6(Jj
} 59L\|OR
input.close(); v~C Czg
} :4w ?#
catch(IOException e){e.printStackTrace ();} A@('pA85
catch(Exception e){e.printStackTrace ();} 3&4(ZH=
} S+6.ZZ9c
M0"_^?
{uFO/
private void processErrorCode(int nErrorCode) Qljpx?E
{ V &T~zh1
System.err.println("Error Code : " + nErrorCode); MJ)RvNF
} D)P._?
W i.&e
VGN5<?PrN
//停止文件下载 UDFDJm$
public void siteStop() (,2SXV
{ h"W,WxL8
bStop = true; A{zN| S[
for(int i=0;i<nStartPos.length;i++) (mB&m@-N
fileSplitterFetch.splitterStop(); |-ALklXr
Rv>-4@fMJ
Q{>k1$fkV
} Yh7t"=o
} KF}hV9IU
//负责部分文件的抓取 Dy&i&5E.-l
**FileSplitterFetch.java Nx;~@
*/ ~8+ Zs
package NetFox; @ q3k%$4
o/)h"i0P
JR|ck=tq
import java.io.*; 1&OW4_
import java.net.*; HJH{nz'Lw
RB\uK 1+
>:!5*E5?
public class FileSplitterFetch extends Thread { _f,C[C[e&
({_{\9O,3
6@!`]tSCK
String sURL; //File URL T>Z<]s
long nStartPos; //File Snippet Start Position 0mVNQxHI
long nEndPos; //File Snippet End Position |r/" |`
int nThreadID; //Thread's ID V0YZp
boolean bDownOver = false; //Downing is over Fo_sgv8O<
boolean bStop = false; //Stop identical H?Wya.7
FileAccessI fileAccessI = null; //File Access interface gQuw1
J;e2&gB
C) s5D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0+ '&`Q!u
{ 5tkAFb4P
this.sURL = sURL; =qIp2c}Rx
this.nStartPos = nStart; B$K=\6o
this.nEndPos = nEnd; Q&;9x?e
nThreadID = id; ?V=ZIGj
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (t|Zn@uY
} w9imKVry
*^4"5X@
n>XdU%&
public void run() <lPG=Xt
{ V!=,0zy~Z
while(nStartPos < nEndPos && !bStop) q;CiV
{ A)!*]o>U
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try{ "S]TP$O D
URL url = new URL(sURL); )&O %*@F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3 i0_hZ
httpConnection.setRequestProperty("User-Agent","NetFox"); BWrxunHO
String sProperty = "bytes="+nStartPos+"-"; BU_nh+dF
httpConnection.setRequestProperty("RANGE",sProperty); AT3Mlz~7#
Utility.log(sProperty); tNI^@xdim1
8nJpp
cT,sh~-x,
InputStream input = httpConnection.getInputStream(); m(!FHPvN
//logResponseHead(httpConnection); Fxz"DZY6
cq]6XK-W
~ 7s!VR
byte[] b = new byte[1024]; q9_OGd|P
int nRead; * u>\57W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o.!Dq7R
{ \b x$i*
nStartPos += fileAccessI.write(b,0,nRead); 2ilQXy
//if(nThreadID == 1) ~0$&3a<n1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FZlWsp=
} oc`H}Wvn
F41=b4/
3 0H?KAV
Utility.log("Thread " + nThreadID + " is over!"); ,"ZMRq
bDownOver = true; oPM96 (
//nPos = fileAccessI.write (b,0,nRead); EQM{
} 7NGxa6wi
catch(Exception e){e.printStackTrace ();} `;C V=,M
} 5;EvNu
} L4HI0Mx
/4Gt{ygSr
jLluj
//打印回应的头信息 R/YqyT\SM
public void logResponseHead(HttpURLConnection con) 5]0<9a
{ %h@EP[\
for(int i=1;;i++) &8lZNv8;(p
{ e"<OELA
String header=con.getHeaderFieldKey(i); L0o\J` :
if(header!=null) GTd,n=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .k !{*
Utility.log(header+" : "+con.getHeaderField(header)); {wKB;?fUvk
else {<KVx9
break; K"MX!
} ]a`$LW}
} (9a^$C*
4Nsp<Kn>
*EH~_F
public void splitterStop() 1qA;/-Zr<o
{ M= (u]%\
bStop = true; !Uo4,g6r+
} ygcm|PrS
MQ2}EY*A
upmx $H>
} mfr|:i
y9ZvV0
!a\^Sk /
/* 75lA%| *X
**FileAccess.java N!}f}oF
*//文件访问(定位，写) %N._w!N<5n
package NetFox; 6gDN`e,@
import java.io.*; {Sh ;(.u^
W>r+h-kR
;$4\e)AB
public class FileAccessI implements Serializable{ RRJ%:5&
L/K(dkx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e0 ecD3
RandomAccessFile oSavedFile; UN#S;x*
long nPos; TWTb?HP
?@x/E&
0y\Z9+G:
public FileAccessI() throws IOException *;FdD{+
{ }GM'.yutX
this("",0); DEgXQ[
} LghfM"g
u ga_T
6u6x
public FileAccessI(String sName,long nPos) throws IOException A#,ZUOPGH
{ ;'1d1\wiDQ
oSavedFile = new RandomAccessFile(sName,"rw"); V7/Rby Q
this.nPos = nPos; xE}>,O|'q
oSavedFile.seek(nPos); 8ao_i=&x
} UiNP3TJ'L
*T1_;4i
{!`6zBsP
public synchronized int write(byte[] b,int nStart,int nLen) #vlgwA
{ lOp`m8_=
int n = -1; %C]>9."
try{ Fr-SvsNFB
oSavedFile.write(b,nStart,nLen); 7tp36TE
n = nLen; l[J8!u2Xp
} 4,ag(^}=
catch(IOException e) zt%Mx>V@
{ WIGi51yC.x
e.printStackTrace (); rJB}qYD
} 9gIrt 6
6]wIG$j
,esmV-
return n; ar,7S&sH
} \U_@S.
eO1lnO|
!VpoZ
} t{>q|0
-?a 26o%e
]M3yLYK/P
/* k?}Zg*
**SiteInfoBean.java dh\P4
*/ =(^3}x
package NetFox; mE[y SrV
V]^$S"Tv
I-)4YQI
public class SiteInfoBean { HaYo!.(Fv
;*J
xSu >
private String sSiteURL; //Site's URL B5QFK
private String sFilePath; //Saved File's Path 5V-I1B&
private String sFileName; //Saved File's Name wIgS3K
private int nSplitter; //Count of Splited Downloading File Bw.i}3UT6
Ys7]B9/1O
73-p*o(pt
public SiteInfoBean() q(w(Sd)#L
{//nSplitter的缺省值为5 X>^fEQq"
//default value of nSplitter is 5 "N#Y gSr
this("","","",5); ^zr`;cJ+c
} i30!}}N8
pCG}ZKa
wC*X4 '
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i/.6>4tE:
{ lquLT6]
sSiteURL= sURL; A}!J$V:w]
sFilePath = sPath; HOi`$vX}N
sFileName = sName; TA\vZGJ('
this.nSplitter = nSpiltter; $~kA B8z
W*G<X.Hf
{`_i`
} +T+#q@
|y*c9
Rb;'O89Hj@
public String getSSiteURL() F"kAkX>3}
{ zm# ?W
return sSiteURL; 3g B7g'U
} `0svy}
/kG_*>.Z
/_.|E]
public void setSSiteURL(String value) IGgL7^MF
{ )5H?Vh>36
sSiteURL = value; Fzcwy V
} }0 ?3:A
iDD$pd,e\
fV~~J2IK
public String getSFilePath() CGFDqCNr-
{ #K&Gp-
return sFilePath; +,l-Nz
} 'fW-Y!k%
4e
y>LBl]
public void setSFilePath(String value) 06jQE2z2R
{ tX[WH\(xI
sFilePath = value; bd`P0f?
} F[MFx^sT{
MfkZ
SfR%s8c`
public String getSFileName() _dU\JD
{ Xc.`-J~Il
return sFileName; #z42C?V
} cb bFw
4!$"ayGv;D
zeRyL3fnmb
public void setSFileName(String value) m+9#5a-
{ 0`H# '/
sFileName = value; qSQ~D(tO
} 1*7@BP5
Zd&S@Z
('~LMu_
public int getNSplitter() @nf`Gw ;
{ |uDdHX8T
return nSplitter; tp|d*7^i
} $Q0n
31)&vf[[
P2Y^d#jO
public void setNSplitter(int nCount) Kpp_|2|@<
{ Y*hCMy;
nSplitter = nCount; h];I{crh
} cCX*D_kCB
} (sj,[
[-&Zl(9&
>dT*rH3w
/* kVL.PY\K
**Utility.java }WV:erg`
*/ pk~WrqK}
package NetFox; M=Wz
)e{}V\;q
QW"! (`K
public class Utility { MQ4KdqgP
$!DpjN
%)wjR/o
public Utility() \v/[6&|X0s
{ Ss`LLq0LO
^}r1;W?n
T0 {Lq:
} r*Xuj=
;d?R:Uw8
//线程睡眠 F[0]/
public static void sleep(int nSecond) ~K=b\xc^
{ hOeRd#AQK
try{ pJ{Y lS{
Thread.sleep(nSecond); <vP=zk
} ?#fQ~ s
catch(Exception e) .^g p?
{ gFh*eCo
e.printStackTrace (); +h$ 9\
} _-\#i
} cZ06Kx..
W8<%[-r
//日志 ,vDbp?)'U
public static void log(String sMsg) d'2A,B~_*
{ liSmjsk
System.err.println(sMsg); w>YDNOk
} <uJ@:oWG7
qWw=8Bq
\DzGQ{`~m
public static void log(int sMsg) @8 6f
{ 3sk9`=[{$
System.err.println(sMsg); $J2Gf(RU
} n*$ g]G$
} Je{ykL?N
:pUtSs7p}
Yw9GN2AG
/* ry!!9Z>9n
**TestMethod.java W4N{S.#!
*/ F5Va+z,jg
package NetFox; j@9T.P1
;);kEq/=P
he4(hX^
public class TestMethod { Y0>y8UV
*2?@ |<(r
&FD>&WRV
public TestMethod() iB{V^ksU
{ ///xx/weblogic60b2_win.exe fIF8%J ^3
try{ 7 3m1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $^P0F9~0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ZW}_DT0
SiteFileFetch fileFetch = new SiteFileFetch(bean); l,8##7
fileFetch.start(); MPV5P^@X
} nR~(0G,H
catch(Exception e){e.printStackTrace ();} nK,w]{<wG!
hQi2U
}*-@!wc-N
} 9iq_rd]
o@Oqm>]SS
nlYNN/@"
public static void main(String[] args) OCUr{Nh
{ kl`W\tF
new TestMethod(); HhpDR
} 68 sB)R
} ;fJ.8C
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