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)); {!=2<-Aq
} ;3UvkN
for(int i=0;i<nEndPos.length-1;i++) 3;y_mg
{ E@pFTvo
nEndPos = nStartPos[i+1]; F=i!d,S
} NI\H \#bJ
nEndPos[nEndPos.length-1] = nFileLength; h{/ve`F>@
} x,1=D~L}
} S=O$JP79
_,Q[2gQ5N
!K\itOEP-
//启动子线程 8c).8RLf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mP!N<K
for(int i=0;i<nStartPos.length;i++) ) `I=oB
{ an KuTI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h5!d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \)R-A '*U
nStartPos,nEndPos,i); e\.HWV]I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); };p~A-E=
fileSplitterFetch.start(); Gl>E[iO
} }ecsGw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /"MJkM.~E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1S*P"8N}0h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~4^p}{
nEndPos = " + nFileLength); @1.9PR$x
// fileSplitterFetch[nPos.length-1].start(); ]fC7%"nB
][t6VA
owMmCR
//等待子线程结束 oD,C<[(p
//int count = 0; UTX](:TC
//是否结束while循环 wlVvxX3%
boolean breakWhile = false; s3< F
.. UoyBV
<[9?Rj@
while(!bStop) (nz}J)T&
{ :c<*%*e
write_nPos(); SG`)PW?
Utility.sleep(500); #eLN1q&Z
breakWhile = true; OPiaG!3<
M.[wKGX(
K;C_Z/<%
for(int i=0;i<nStartPos.length;i++) VN+\>j-
{ w, 7Cr
if(!fileSplitterFetch.bDownOver) z1Q2*:)c
{ *(nJX.7
breakWhile = false; 5H!%0LrJg=
break; WRM$DA
} \n(ROf^'
} ai^t= s
if(breakWhile) Bb_Q_<DTs
break; >)y$mc6
YkI9d&ib+
DZP*x
//count++; 1RA }aX
//if(count>4) <Wf0QO,
// siteStop(); )JX$/- RD-
} hr1$1&p
.qinR6=
9A<0zt
System.err.println("文件下载结束！"); mt^`1ekoY
} InN{^uN
catch(Exception e){e.printStackTrace ();} cD8Ea(
} @T/qd>T o
GEfY^!F+
U2UyN9:6F
//获得文件长度 :iEAUM
public long getFileSize() 9'X@@6b*'
{ _XWnS9
int nFileLength = -1; P4[]qbfd,
try{ @it/$>R^)
URL url = new URL(siteInfoBean.getSSiteURL()); e&ts\0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +9_,w bF
httpConnection.setRequestProperty("User-Agent","NetFox"); '$*[SauAG
D&f!( n
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int responseCode=httpConnection.getResponseCode(); WP!il(Gr
if(responseCode>=400) F-tFet
{ dm 2EH
processErrorCode(responseCode); 9.]kOs_
return -2; //-2 represent access is error `fMpV8vv
} ()B7(Y
9R>~~~{-Go
r},lu=em
String sHeader; !"%S#nrL$
vlAy!:CV
`Jqf**t
for(int i=1;;i++) F;W'
{ aPt{C3<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N5ci};?
//Utility.log(in.readLine()); a_AJ)4
sHeader=httpConnection.getHeaderFieldKey(i); /]g>#J%b
if(sHeader!=null) My],6va^
{ EO"6Dq(
if(sHeader.equals("Content-Length")) FNlx1U[
{ yeNvQG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g<a<{|
break; _1\poAy
} ?ff [$ab
} %VS 2M #f
else c l9$g7
break; PMY~^S4O
} jVs(x
} X]MTaD.t
catch(IOException e){e.printStackTrace ();} FF jRf
catch(Exception e){e.printStackTrace ();} p$XnOh
Qqh^E_O
lm!FM`m
Utility.log(nFileLength); ]h0Y8kpd
|lY`9-M`I
Z) t{JHm:
return nFileLength; "H@Fe
} Eny!R@u7q
z:?:
{H'X)n$
//保存下载信息（文件指针位置） ~\3l!zIq
private void write_nPos() mfz"M)1p1
{ `}Eh[EOHJ
try{ lj Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z"]xdOre
output.writeInt(nStartPos.length); $q^O%(
for(int i=0;i<nStartPos.length;i++) sN=KRqe
{ vv!Bo~L1,
// output.writeLong(nPos); 8ZFH}v@V1'
output.writeLong(fileSplitterFetch.nStartPos); shD+eHo$
output.writeLong(fileSplitterFetch.nEndPos); PH[4y:^DN
} i:{:xKiCa
output.close(); IE|,~M2
} fmBkB8
catch(IOException e){e.printStackTrace ();} >r~|1kQ.
catch(Exception e){e.printStackTrace ();} y=wdR|b
} E~}[+X@
y%JF8R;n
m+p4Mc%u
//读取保存的下载信息（文件指针位置） yZ?$8r
private void read_nPos() x!>d 6lgej
{ pA*i!.E/b
try{ aw]8V:)$J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k,AM]H
int nCount = input.readInt(); uRFNfX(*
nStartPos = new long[nCount]; 8cB=}XgYS
nEndPos = new long[nCount]; @::lJDGVv
for(int i=0;i<nStartPos.length;i++) ? 1GJa]G
{ TX&[;jsj
nStartPos = input.readLong(); ~6] )*y
nEndPos = input.readLong(); $G)&J2zL
} 75<el.'H
input.close(); )Gmb?!/^
} 3mybG%39
catch(IOException e){e.printStackTrace ();} am3V9"\
catch(Exception e){e.printStackTrace ();} uht(3
} $vz_%Y
OW?uZ<z
>=bt
private void processErrorCode(int nErrorCode) X,&`WPA:S
{ 0,bt^a
System.err.println("Error Code : " + nErrorCode); V,E9Uds
} bKTqX[=
Sio1Q0
ykJ+%gla
//停止文件下载 zI(xSX@
public void siteStop() 5[1@`6j
{ .iN-4"_j1
bStop = true; vs*>onCf
for(int i=0;i<nStartPos.length;i++) *13g<#$
fileSplitterFetch.splitterStop(); u4@, *tT
2m|Eoc&M_
hjw4Xzju
} t2~"B&7My
} /nwxuy
//负责部分文件的抓取 uwmoM>I W^
**FileSplitterFetch.java 6Q?BwD+>
*/ :vw0r`
package NetFox; 1<;\6sg
eog\pMv
U<K|jsFo
import java.io.*; 7?+5%7-
import java.net.*; ^tQPJ
0kkRK*fp}x
'9f6ZAnYpQ
public class FileSplitterFetch extends Thread { 7sCR!0
o7m99(
6Wf*>G*h
String sURL; //File URL v`@5enr
long nStartPos; //File Snippet Start Position ;OQ#@|D
long nEndPos; //File Snippet End Position )Uc$t${en
int nThreadID; //Thread's ID !."Izz/
boolean bDownOver = false; //Downing is over ]r"31.w(
boolean bStop = false; //Stop identical ~GAlNIv]
FileAccessI fileAccessI = null; //File Access interface h<+PP]l=
-7&^jP\,
?T tQZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dl7Riw-J
{ Q]yV:7
this.sURL = sURL; L[`R8n1C
this.nStartPos = nStart; SJso'6 g
this.nEndPos = nEnd; )e@01l
nThreadID = id; Z|V"8jE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MA~|y_V
} H(
=1%zI%
iK$Vd+Lgc
public void run() f6keWqv<GW
{ JsZAP
while(nStartPos < nEndPos && !bStop) %@M00~-
{ 7f.4/x^
!%SdTaC{T
)6O\WB|
try{ nXx6L!HJ#
URL url = new URL(sURL); p~,a=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |#Yu.c*
httpConnection.setRequestProperty("User-Agent","NetFox"); eD>-`'7<
String sProperty = "bytes="+nStartPos+"-"; }S'I DHla
httpConnection.setRequestProperty("RANGE",sProperty); Km|9Too
Utility.log(sProperty); Zm"!E6`69
h;cB_6vt
G1`mn$`kq
InputStream input = httpConnection.getInputStream(); w`H.ey
//logResponseHead(httpConnection); [Q2S3szbt6
DLwC5Iir
<~IH`
byte[] b = new byte[1024]; "1gk-
int nRead; 0 .6X{kO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3B!&ow<rt
{ Zztt)/6*
nStartPos += fileAccessI.write(b,0,nRead); ];d5X
//if(nThreadID == 1) orcZyYU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mh!N^[=n
} ihpz}g
89:?.'
|k['wqn"
Utility.log("Thread " + nThreadID + " is over!"); =F^->e0N
bDownOver = true; S*2L4Uj`|
//nPos = fileAccessI.write (b,0,nRead); Knw'h;,[
} 1pYmtr
catch(Exception e){e.printStackTrace ();} ~P"!DaAf
} hy!'Q>[`
} WwCK K
-N-4l
82Z[eo
//打印回应的头信息 %%-U.
public void logResponseHead(HttpURLConnection con) kMJQeo79
{ T}b( M*E
for(int i=1;;i++) O3<Y_I^
{ 2]_4&mU
String header=con.getHeaderFieldKey(i); $Z(g=nS>
if(header!=null) x[.z"$T@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XEgx#F ;F
Utility.log(header+" : "+con.getHeaderField(header)); dEAAm=K,<
else u75)>^:I
break; _($-dJ{
} vxzf[
} gn[$;*932z
?-.Ep0/
nY"rqILX?
public void splitterStop() 5.C[)`_
{ 0]2B-o"kI
bStop = true; $@:>7Y"
} D"(3VIglq
q_T?G e
:}3qZX
} i Ks,i9j
.olPm3MC
\$~oH3m&
/* n[MIa]dK
**FileAccess.java t\|K"
*//文件访问(定位，写) Z9 q{r s
package NetFox; xJH9qc ME
import java.io.*; 'j,Li(@}
2 Zjb/
hO<w]jV,
public class FileAccessI implements Serializable{ :9rhv{6Wp
\Q?|gfJH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?C>VB+X}y
RandomAccessFile oSavedFile; X?}GPA4 W
long nPos; g`5`KU|
}2!5#/^~
Mp=kZs/
public FileAccessI() throws IOException "TH-A6v1
{ {+UNjKQC
this("",0); M;TfD
} 7^t(RNq
'*LN)E>d
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public FileAccessI(String sName,long nPos) throws IOException U37?P7i's
{ gq:TUvX
oSavedFile = new RandomAccessFile(sName,"rw"); vL=--#
this.nPos = nPos; [TfV2j* e
oSavedFile.seek(nPos); f$S QhK5`
} []N$;~R7
uA/.4 b
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public synchronized int write(byte[] b,int nStart,int nLen) +D-+}&oW
{ t>h i$NX{p
int n = -1; d @kLLDP
try{ qL;T&h
oSavedFile.write(b,nStart,nLen); d_7Xlp@
n = nLen; io33+/
} F?,&y)ri
catch(IOException e) .bBQhf.&"
{ _kY[8e5
e.printStackTrace (); %d#)({N
} 0|>
v7OV;ea$
[oN> :
return n; 6ewOZ,"j"4
} ^Er`{|o6u
#IrP"j^
z&vms
} nIDsCu=A
6'*Uo:]
DUliU8B}\
/* 6.7Kp
**SiteInfoBean.java `rdfROKv
*/ Jx>B %vZ\
package NetFox; aC }1]7
jhbH6=f4]^
dQ|Ht[s=
public class SiteInfoBean { U+r#YE.
~)8i5p;P/k
'U{: zBh
private String sSiteURL; //Site's URL m"7R 4O
private String sFilePath; //Saved File's Path m'"VuH?^
private String sFileName; //Saved File's Name 6')SJ*|yS
private int nSplitter; //Count of Splited Downloading File +U)|&1oa
UpseU8Wo
x&/Syb
public SiteInfoBean() kDP^[V P+
{//nSplitter的缺省值为5 .-~%w
//default value of nSplitter is 5 -&D6w9w
this("","","",5); j~f 7WJ
} B:#0B[
G/3lX^Z>
H1qw1[%0y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Dlf=N$BL7d
{ m9w ;a
sSiteURL= sURL; I"<. h'
sFilePath = sPath; ZjW| qb
sFileName = sName; OSi9J.]O
this.nSplitter = nSpiltter; \bA'Furp
j?hyN@ns
Pc4cSw#5
} Y'*h_K
#(J}xz;
/_\W*@ E
public String getSSiteURL() Prx s2 i 8
{ }gRLW2&mR>
return sSiteURL; n(Op<
} {&qsh9ob
G*p.JsZP
%)ov,p|
public void setSSiteURL(String value) 6;XpLivP7
{ ibUPd."W
sSiteURL = value; `|?$; )
} vbh#[,lh
grAL4
1Klu]J%
public String getSFilePath() p&doQh
{ .h^Ld,Chj
return sFilePath; 0%j;yzQ<
} S9+gVR8]C
3"D00~
e;r-}U
public void setSFilePath(String value) 2+cicBD
{ ;K-t
sFilePath = value; , )3+hnFY
} iGNKf|8{
LOkDx2@g
|noTIAI
public String getSFileName() g~u!,Zc
{ yN%Pe:R
return sFileName; 4zbV' ]
} _Fy:3,(
X]%4QIeS
\9Zfu4WR
public void setSFileName(String value) W0hLh<Go
{ VQ`O;n6/`
sFileName = value; ?Kf@/jv
} _: x$"i
{'[1I_3
'(*D3ysU
public int getNSplitter() hG)lVo!L4j
{ euK!JZ
return nSplitter; ['j,S<Bu~
} \GPc_m:qL
0Jrk(k!
dl4.jLY
public void setNSplitter(int nCount) q\<vCKI-^
{ DJ.Ct4
nSplitter = nCount; ]]4E)j8
} (g\'Zw5bk
} i F Ab"VA
d?>sy\{2
=Ev } v
/* &uM?DQ`o8
**Utility.java wU3Q
*/ J=sQ].EK
package NetFox; G7yxCU(I\
TBpW/wz/
9Y(<W_{/
public class Utility { ``={FaV~m
~I'hiV^-
`CV a`%
public Utility() QwiC2}/
{ 3^Ex_jeB
k~H-:@
h)w<{/p(
} JS4pJe\q
e2;">tp6?
//线程睡眠 _K8-O>I "
public static void sleep(int nSecond) jN[Z mJz'
{ *I~F7Z]|
try{ PW}Yts7p
Thread.sleep(nSecond); %!WQ;(
} +^`c"qJo
catch(Exception e) Uq"RyvkpP
{ }Za[<t BWS
e.printStackTrace (); c!s{QWd%
} N!hp^V<7
} ww=< =
5Pn$@3
//日志 W/fM0=!
public static void log(String sMsg) ~bgFU
{ F+9|D
System.err.println(sMsg); ?"J5~_U.
} ,)%nLc
az7L0pp
F)!B%4
public static void log(int sMsg) {n{ j*+
{ b5KX`r
System.err.println(sMsg); }KJ/WyYW
} UtY<R
} %WdAI,
E+csK*A7
ASPfzW2
/* P3);R>j
**TestMethod.java !%sj-RMvG
*/ 4WU 6CN
package NetFox; (7&[!PS
k(!#^Mlz[
cl)%qIXj}H
public class TestMethod { {-tCLkE 3
nTp?
x_AG=5OJX,
public TestMethod() >4b-NS/}0
{ ///xx/weblogic60b2_win.exe k oZqoP
try{ Qgf\gTF$r+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u0Irf"Ab
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "=N[g
SiteFileFetch fileFetch = new SiteFileFetch(bean); !Zlvz%X
fileFetch.start(); ){ArZjG>
} FlgK:=Fmj
catch(Exception e){e.printStackTrace ();} fMP$o3;
h1q?kA
X70G@-w
} 2y`rS _2
R6ca;
XSkx<"U*
public static void main(String[] args) o!dTB,Molr
{ T&j_7Q\;vI
new TestMethod(); \J.PrE'(}
} :?O+EE
} !:'%'@uc
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