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)); KWhZ +i`
} - 8bNQU
for(int i=0;i<nEndPos.length-1;i++) '{f=hE_/
{ S#8>ZwQ
nEndPos = nStartPos[i+1]; F9H~k"_ZJR
} (][LQ6Pc
nEndPos[nEndPos.length-1] = nFileLength; d~*TIN8Ke~
} {8@\Ij
} N[Sb#w`[/
_3>djF_u
O8|*M "
//启动子线程 b |7ja_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y)b@0'
for(int i=0;i<nStartPos.length;i++) ZPO|<uR
{ 7*s8ttX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RFko>d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "Xn%at4
nStartPos,nEndPos,i); 9"sDm}5%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t`|,6qEG
fileSplitterFetch.start(); V U~Dk);Bv
} #Hu~}zy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ip?]K*sq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); op7FZHs
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UG2w 1xqHw
nEndPos = " + nFileLength); lBA+zZ
// fileSplitterFetch[nPos.length-1].start(); NY.k.
<]G${y*;
P<;7j?
//等待子线程结束 ?KWj}|%
//int count = 0; *'R#4@wmP
//是否结束while循环 A0xC,V~z
boolean breakWhile = false; ~kKrDLW+
&L4 q10-N
i0pU!`0
while(!bStop) ~]uZy=P? 5
{ A6UO0lyu
write_nPos(); uDayBaR
Utility.sleep(500); ^O6*e]C$
breakWhile = true; [-w@.^:]X
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nr2r8u9r
for(int i=0;i<nStartPos.length;i++) Llz['"m
{ HDIk9WC^
if(!fileSplitterFetch.bDownOver) Z=+03
{ NZXjE$<Vr
breakWhile = false; Lz4ehWntO
break; Bw<rp-
} Z1,gtl ?
} Hs0pW5oZ
if(breakWhile) E9 Y\X
break; 9=+-QdX+0]
WZFH@I28
1BTIJ Gw
//count++; 9dKul,c
//if(count>4) 7#2j>G{?]v
// siteStop(); >nnY:7m
} ! D1zXXq
v\0^mp
q=0 pQ1>
System.err.println("文件下载结束！"); %z)EO9vtr
} J$[Q?8 ka
catch(Exception e){e.printStackTrace ();} nQLs<]h1
} 3|eUy_d3
9g@NcJ]
{;n0/
//获得文件长度 DY3:#X`4
public long getFileSize() n|KKby.$
{ a%J/0'(d
int nFileLength = -1; ?qT(3C9p
try{ -9&g[
URL url = new URL(siteInfoBean.getSSiteURL()); *cNk>y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7),*3c')
httpConnection.setRequestProperty("User-Agent","NetFox"); GX38~pq
O E|+R4M
B,y3] g6u
int responseCode=httpConnection.getResponseCode(); -!R l(if
if(responseCode>=400) &?T${*~
{ gCV rC
processErrorCode(responseCode); 0wvU?z%WK
return -2; //-2 represent access is error JDhwN<0R
} 9d\N[[Vu]R
S0xIvzS
'Y)/~\FI
String sHeader; [.3sE
+x]e-P%
- L`7+
for(int i=1;;i++) uUS)#qM|
{ ^ f{qJ[,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q8Te'1Ln!
//Utility.log(in.readLine()); ^H!Lp[5c
sHeader=httpConnection.getHeaderFieldKey(i); i+ic23$4M
if(sHeader!=null) r@|ZlM@O
{ b]#~39Iph
if(sHeader.equals("Content-Length")) `A{'s %$?!
{ m+T2vi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4
break; z7q%,yw3N
} rWe 8D/oc
} SALCuo"L
else { _X#fq0}
break; Cyf]`*
} 3@HIpQM3
} 8S=c^_PJ
catch(IOException e){e.printStackTrace ();} e7|d=[kW
catch(Exception e){e.printStackTrace ();} sZm^&h;
Q)dT(Td9~
%kW3hQ<$
Utility.log(nFileLength); qKs7WBRJy
OR~GOv|
g& >mP?
return nFileLength; Eq7gcDQ
} G>j"cj
+V89J!7
S41)l!+2
//保存下载信息（文件指针位置） f#c BQ~
private void write_nPos() =U_@zDD@V
{ B>aEHb
try{ !vrnoFVu
output = new DataOutputStream(new FileOutputStream(tmpFile)); VY{,x;O`
output.writeInt(nStartPos.length); nOr"K;C
for(int i=0;i<nStartPos.length;i++) -;S3|
{ F]SIT\kBm
// output.writeLong(nPos); 4^BLSK~(
output.writeLong(fileSplitterFetch.nStartPos); %Fm`Y.l
output.writeLong(fileSplitterFetch.nEndPos); gQCC>8
} C=EhY+5
output.close(); 8fEAYRGd
} Oo$%Yh51~
catch(IOException e){e.printStackTrace ();} eo]a'J9(
catch(Exception e){e.printStackTrace ();} x"!#_0TT}
} GiFf0c 9
#PPsRKj3c
98ayA$
//读取保存的下载信息（文件指针位置） I')x]edU
private void read_nPos() cnYYs d{
{ C}bPv+t
try{ *fOIq88
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DW4MA<UQ
int nCount = input.readInt(); ls]Elo8h1f
nStartPos = new long[nCount]; 5I_hh?N4Z
nEndPos = new long[nCount]; ]q37Hj
for(int i=0;i<nStartPos.length;i++) *<;&>w8
{ =mAGD*NKu
nStartPos = input.readLong(); ]X4RnV55Q
nEndPos = input.readLong(); &U854
} ur`}v|ZY
input.close(); @US '{hO1p
} ~.!?5(AH8z
catch(IOException e){e.printStackTrace ();} /$<JCNGv
catch(Exception e){e.printStackTrace ();} +Hi{/{k0N
} uk1v7#p
" gwm23Rpj
0sY#MHPT&
private void processErrorCode(int nErrorCode) P[6dTZ!\s
{ #C'o'%!(
System.err.println("Error Code : " + nErrorCode); 0n7HkDo
} ^M"HSewo
b^;N>zx
}v,W-gA
//停止文件下载 ?|gGsm+
public void siteStop() WMRYT"J?N]
{ 8UlB~fVg
bStop = true; YDdLDE
for(int i=0;i<nStartPos.length;i++) JO]`LF]
fileSplitterFetch.splitterStop(); :v''"+\
WJBW:2=;
(#CBq
} EPR(i#xU
} }NR`81
//负责部分文件的抓取 ~rQ4n9G
**FileSplitterFetch.java 0 %C!`7
*/ U_.n=d~B
package NetFox; k_-vT
'aLPTVM^
lu<Np9/5<
import java.io.*; {8ld:ZP
import java.net.*; 1Qrm"TFo
H@Kl
zvWO4\
public class FileSplitterFetch extends Thread { zS,%msT^A
44g`=o@
^?81.b|qb
String sURL; //File URL !Q<8c =f
long nStartPos; //File Snippet Start Position Fwg#d[:u
long nEndPos; //File Snippet End Position mw2rSUI{
int nThreadID; //Thread's ID ZY~zpC_
boolean bDownOver = false; //Downing is over _D!M nTK
boolean bStop = false; //Stop identical (mu{~@Hw
FileAccessI fileAccessI = null; //File Access interface kJVM3F%
zlC^
la!1[VeL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v GulM<YY
{ N8u_=b{X
this.sURL = sURL; hXj* {vT
this.nStartPos = nStart; >Lo6='G
this.nEndPos = nEnd; :qt82tbn
nThreadID = id; 6:8EZ'y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }UJdE#4
} 6kgCS{MZ
(UbR%A|v;
Q-H=wJ4R
public void run() ./aZV
{ Q;{D8 #!
while(nStartPos < nEndPos && !bStop) 9RbGa Y&
{ :8p2Jxm
dn:|m^<)
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try{ \= )[
URL url = new URL(sURL); (\[jf39e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3D[:Rf[
httpConnection.setRequestProperty("User-Agent","NetFox"); YA1{-7'Q
String sProperty = "bytes="+nStartPos+"-"; ]JhDRJ\
httpConnection.setRequestProperty("RANGE",sProperty); 7%~VOB
Utility.log(sProperty); Sm~? zU[k/
WVBE>TB
64IeCAMVo
InputStream input = httpConnection.getInputStream(); }V93~>
//logResponseHead(httpConnection); XPR:_
[:/7OM
/cn/[O9
byte[] b = new byte[1024]; b[QCM/
int nRead; u0(hVK`":
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q>#)LHX
{ Yg]FF`{p=
nStartPos += fileAccessI.write(b,0,nRead); ;$k?&nhY
//if(nThreadID == 1) [57V8%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }(f,~?CP]
} $u0+29T2O
1.ugXD
FW6E)df
Utility.log("Thread " + nThreadID + " is over!"); f%(e,KgW=
bDownOver = true; \?p9qR;"4
//nPos = fileAccessI.write (b,0,nRead); h}c6+@w&-
} 10QNV=yK7s
catch(Exception e){e.printStackTrace ();} uBd =x<c\
} oPCIlH
} P+_\}u;
L?/M2zc9Y
&Pn%zfmMN
//打印回应的头信息 'J&@jp
public void logResponseHead(HttpURLConnection con) cfO^CC
{ )f_"`FH0d
for(int i=1;;i++) k[^}ld[
{ fmT3Afl5c
String header=con.getHeaderFieldKey(i); JOL Z2
if(header!=null) d}^:E
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e[|p0 ,Q
Utility.log(header+" : "+con.getHeaderField(header)); s$3eJ|
else BLYk <m
break; V< 9em7
} O!@KM;
} ;d'O.i=
uDMUy"8&!
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public void splitterStop() FC/>L
{ A16-
bStop = true; u3ri6Y`
} wft:eQ
/Va&k4
SgQmYaa&
} .k?hb]2N
t]YLt ,
rym\5 `)
/* L_CEY
**FileAccess.java 3YZ3fhpw
*//文件访问(定位，写) /:c,v-
package NetFox; UmHJ/DI@
import java.io.*; lhvZ*[[<)
hH@o|!y
9zM4D
public class FileAccessI implements Serializable{ L-oPb)
|^&2zyUj/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XP Iu]F
RandomAccessFile oSavedFile; }E\+e!'!2
long nPos; .L5T4)
D} <o<Dk
crOtQ
public FileAccessI() throws IOException <@;xV_`X+
{ d .lu
this("",0); t$kf'An}/
} )]e d;V
V,*0<7h
?@uK s4
public FileAccessI(String sName,long nPos) throws IOException ?PU(<A+
{ ,`B>}
oSavedFile = new RandomAccessFile(sName,"rw"); -|iA!w#31
this.nPos = nPos; }A&Xxh!Fwo
oSavedFile.seek(nPos); vpr@
} g he=mQ-
,-NLUS "w
YH'.Yj2
public synchronized int write(byte[] b,int nStart,int nLen) :!*;0~#
{ uu46'aT
int n = -1; yl]Cm?8
try{ Ss#{K;
oSavedFile.write(b,nStart,nLen); JqV<A3i
n = nLen; J*4_|j;Z-E
} \crb&EgID
catch(IOException e) JbD)}(G;
{ Vm%ux>}
e.printStackTrace (); sOtNd({
} 6W#F Ss~
tFP;CW!E
|$*9j""u
return n; 6"c!tJc7j
} M97p.;;
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\?]HqPibx
} *V<2\-
6'lT`E|
[q|Q]O0
/* #mFAl|O
**SiteInfoBean.java VDI S`E
*/ >IydXmTy
package NetFox; Spw=+z<<Ub
P`Wf'C^h
/r 2.j3:l
public class SiteInfoBean { U~`^Y8UF
/01(9(
(DaP~*c3cC
private String sSiteURL; //Site's URL tNNg[;0
private String sFilePath; //Saved File's Path eOnl sx/
private String sFileName; //Saved File's Name lSsFI30
private int nSplitter; //Count of Splited Downloading File \kRJUX!s
TKutO0
x?&xz;
public SiteInfoBean() i{RS/,h4
{//nSplitter的缺省值为5 q9Opa2
//default value of nSplitter is 5 2o7C2)YT$
this("","","",5); U=?"j-wN
} g,]5&C T3v
-VT?/=Y s
+o70:UF%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *:\9T#h
{ d:''qgz`
sSiteURL= sURL; [_-K
sFilePath = sPath; KA#-X2U/
sFileName = sName; Hkt'~L*
this.nSplitter = nSpiltter; ]0le=Ee^%
+s}28U!
ZZ5yu* &
} 78-:hk
quYZD6IH
s#[Ej&2[=
public String getSSiteURL() STI3|}G*P
{ &i!]
return sSiteURL; )frtvN7
} A9gl|II
iz(+(M
'3VrHL@@g
public void setSSiteURL(String value) f7s.\
{ Dn?L
sSiteURL = value; jGCW^#GE
} cD6o8v4]]
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bJD"&h5
public String getSFilePath() ='j
{ Z5=!R$4
return sFilePath; V'$ eun
} 4J1Q])G9
fZO/HzX
/'(P{O>{j
public void setSFilePath(String value) E=d[pI,e
{ 2LdV=ifq2S
sFilePath = value; ^l,Jbt
} n6}1{\
Zn//u<D
u4'Lm+&O
public String getSFileName() >Z%^|S9
{ :xV&%Qa1
return sFileName; 4 #N#[;M
} /a_|oCeC}
eC-TZH@
P+SCX#{y
public void setSFileName(String value) 49m/UeNZ
{ |D~MS`~qd5
sFileName = value; Ft}tIP7
} OjI*HC
hbK+\X
t-Wn@a
public int getNSplitter() =DgD&_
{ DxBt83e
return nSplitter; &}uO ]0bR
} pK`rm"6G
itU01
l O^h)hrR
public void setNSplitter(int nCount) V4H+m,R
{ @b zrJ7$
nSplitter = nCount; MqqS3
} a#1X)ot
} AN;?`AM;
WA/\x
BhjXNf9[
/* ^:0?R/A
**Utility.java `3-j%H2R
*/ dXj.e4,m
package NetFox; i@RjG
P<hqr;
-~q]0>
public class Utility { o\#C] pp
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public Utility() ]V_9[=%
{ 0)B+:
MouYZI)
wg_Z!(Hr#
} l;2bBx7vW
s$en5)
//线程睡眠 g`j%jQuY
public static void sleep(int nSecond) 2I7P}=
{ +*dJddz
try{ HUJ $e2[
Thread.sleep(nSecond); !ZVMx*1Cf
} Y5 dt?a
catch(Exception e) }?JO[Q +
{ Q pX@;j
e.printStackTrace (); YpL}R#
} xR.Ql>
} mKg~8q 3
L,<.rr$:
//日志 u{ng\d*KE}
public static void log(String sMsg) J L3A/^
{ ,P|PPx%@
System.err.println(sMsg); V)`?J)
} _#_Ab8#
cZYX[.oIB
#k6;~
public static void log(int sMsg) X[w9~t$\
{ -zkB`~u_
System.err.println(sMsg); QUNsS9
} Nl+2m4
} 1/m/Iw@
86_Zh5:
O ?4V($
/* Q,$x6YwE
**TestMethod.java ;i]cmy
*/ R Q8okA
package NetFox; 5s>9v
A1C@'9R*
LF0~H}S;6B
public class TestMethod { vV|egmw01
T:ck/:ZH
5HU>o|.
public TestMethod() 2{&" 3dq
{ ///xx/weblogic60b2_win.exe J4gIkZD
try{ >3bpa<M_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A!J5Wz>Q5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WC4Il C
SiteFileFetch fileFetch = new SiteFileFetch(bean); #GF1MFkoS
fileFetch.start(); I#0.72:[
} Z-Uq89[HZ
catch(Exception e){e.printStackTrace ();} GgtL./m
WO{N@f^
T \AuL
} arB$&s
K5KN}sRs"
6Z"%vrH
public static void main(String[] args) Wp'\NFe8
{ D>mLSh
new TestMethod(); #0R;^#F/
} xv2;h4{<
} gO5;hd[l
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