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)); gLzQM3{X9
} q(s&2|
for(int i=0;i<nEndPos.length-1;i++) LDgGVl
{ 2)F~
nEndPos = nStartPos[i+1]; rYfN
} Z[GeU>?P
nEndPos[nEndPos.length-1] = nFileLength; B.Y8O^rx
} tPz!C&.=
} 2PDU(R
LSlYYyt
G9AQIU%ii
//启动子线程 cKe{ ]a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &fRZaq'2R
for(int i=0;i<nStartPos.length;i++) tg"NWp6
{ =C4!h'hz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SLjSNuOP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "eH.<&
nStartPos,nEndPos,i); ]1dnp]r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ud$*/ )/
fileSplitterFetch.start(); ~\o hH
} 8h$f6JE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @A1Ohl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d3&l!DoX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AD@-H0Y
nEndPos = " + nFileLength); =g^k$ Rc
// fileSplitterFetch[nPos.length-1].start(); Jf3xK"in
>`)IdX
A[8vD</}_
//等待子线程结束 }~+_|
//int count = 0; nS9 kwaO
//是否结束while循环 ATkx_1]KM-
boolean breakWhile = false; 0UN65JBuD
vE$n0bL2
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while(!bStop) R.)w l
{ w<$0n#5
write_nPos(); KlSg0s
Utility.sleep(500); 2&KM&NX~
breakWhile = true; th]pqhl>
}:xj%?ki
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for(int i=0;i<nStartPos.length;i++) 4)z*Vux
{ 6$x9@x8
if(!fileSplitterFetch.bDownOver) r NT>{
{ T@gm0igW/;
breakWhile = false; aF5=k:k
break; c?7Wjy
} tXW7G@
} "iPX>{'En
if(breakWhile) Xb\de_8!
break; "[Hn G(gA
vfpK|=[7o
rw%1>]os
//count++; Nny#}k Bt
//if(count>4) {-.ZFUZmT
// siteStop(); ' "I-! +
} bPHtP\)
qN@0k>11?
w[hT,$n
System.err.println("文件下载结束！"); <NlL,
} k:*(..!0z
catch(Exception e){e.printStackTrace ();} NsUP0B}.
} (GB*+@
y*7<tj.`b0
#J|DW C!#d
//获得文件长度 U%H6jVE
public long getFileSize() jPA^SxM
{ YAJr@v+Ls
int nFileLength = -1; M#o'hc
try{ F_z1ey`t
URL url = new URL(siteInfoBean.getSSiteURL()); 3.E3}Jz`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -YJ4-]Z
httpConnection.setRequestProperty("User-Agent","NetFox"); z=pGu_`2
\+VQoB/
v|@1W Uc,g
int responseCode=httpConnection.getResponseCode(); %(i(Cf8@
if(responseCode>=400) m$WN"kV`,9
{ pL pBP+i
processErrorCode(responseCode); ,l7',@6Y
return -2; //-2 represent access is error L{uQ:;w1
} *G(ZRj@33
{~{</ g/
v/z~ j
String sHeader; EU4j'1!&g<
'-NHu +
r0j+P%
for(int i=1;;i++) tA{?-5
{ $i;_yTht
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $Fik]TbQp
//Utility.log(in.readLine()); 7?a!x$-U(
sHeader=httpConnection.getHeaderFieldKey(i); gSt'<v
if(sHeader!=null) B0$.oavC
{ [&K"OQ^\2h
if(sHeader.equals("Content-Length")) /\u1q<
{ ZDTp/5=?K/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jrZH1dvE
break; 3Q~zli:
} /Q\|u:oO,
} JsV-:J
else DxJY{e9
break; B(qwTz 51
} !B:wzb_
} c'&\[b(m
catch(IOException e){e.printStackTrace ();} YW'l),Z
catch(Exception e){e.printStackTrace ();} v%!'vhf_K
5%;=(Oig
3iBUIv
Utility.log(nFileLength); L2{b~`UvP
zIy&gOX
vCsJnKqK
return nFileLength; B f"L;L
} I6RF;m:Jw
[6cf$FS9
gib'f@i;
//保存下载信息（文件指针位置） =v49[i
private void write_nPos() 35Cm>X
{ Bl/Z _@
try{ dz=pL$C
output = new DataOutputStream(new FileOutputStream(tmpFile)); `i{p6-U3
output.writeInt(nStartPos.length); h}yfL@
for(int i=0;i<nStartPos.length;i++) NZ:KJ8ea"
{ 9Je+|+s]
// output.writeLong(nPos); h$$2(!G4
output.writeLong(fileSplitterFetch.nStartPos); "s.s(TR8
output.writeLong(fileSplitterFetch.nEndPos); 5"2pU{xmK
} I,@ 6w
output.close(); ~R C\
} R-OQ(]<*
catch(IOException e){e.printStackTrace ();} eh}I?:(a?
catch(Exception e){e.printStackTrace ();} Wz)@k2
} :[!b";pR
uow{a*qd6
[J +5
//读取保存的下载信息（文件指针位置） =} flmUv~
private void read_nPos() @ w?,7i-S
{ m)e~HP7M
try{ }-T :
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mae@L
int nCount = input.readInt(); *:8,w?Nt
nStartPos = new long[nCount]; M{Hy=:K+
nEndPos = new long[nCount]; mG.H=iw
for(int i=0;i<nStartPos.length;i++) J>Bc-%.Q
{ ]7J*(,sp
nStartPos = input.readLong(); Hd?#^X
nEndPos = input.readLong(); A&L2&ofV&q
} !MEA@^$#
input.close(); V*H7m'za
} CMC9%uq
catch(IOException e){e.printStackTrace ();} Q(/F7"m
catch(Exception e){e.printStackTrace ();} [1g
} xaNM?]%
Z=zD~ka
&FY7 D<
private void processErrorCode(int nErrorCode) F`M`c%
{ Dn@Sjsj>
System.err.println("Error Code : " + nErrorCode); A}G>JL
} _NN5e|t
kS<9cy[O
Lv7$@|"H9
//停止文件下载 z@U5
public void siteStop() DT3koci(
{ _ pO1XM
bStop = true; M+-1/vR *@
for(int i=0;i<nStartPos.length;i++) {;+9A}e
fileSplitterFetch.splitterStop(); l\HtP7]
v%;Nyab6$
\ k &ZA
} SY$%)(c8kL
} 8XD_p);Oy
//负责部分文件的抓取 %,f(jQfg_
**FileSplitterFetch.java S#N4!"
*/ Vu;z|L
package NetFox; lN'b"N
+k\cmDcb
S3gd'Bahq
import java.io.*; b] ~
import java.net.*; L16">,5
$Go)Zs-bL?
q@XxCP]
public class FileSplitterFetch extends Thread { 7',WLuD
Qq3UC%Z1
Ue(\-b\)
String sURL; //File URL >f*Zf(F
long nStartPos; //File Snippet Start Position gXe`G(w
long nEndPos; //File Snippet End Position \?"p]&2UcB
int nThreadID; //Thread's ID hE;BT>_dn
boolean bDownOver = false; //Downing is over "=!sZO?3
boolean bStop = false; //Stop identical La r9}nx0
FileAccessI fileAccessI = null; //File Access interface s3y"y_u
F.-:4m(Z
?wREX[Tqs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e`zCz`R
{ k:#u%Z
this.sURL = sURL; p{[(4}ql
this.nStartPos = nStart; ,tak{["
this.nEndPos = nEnd; h@fF`
nThreadID = id; qkBCI,X_Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;&$f~P Q
} -ju}I
Zx)gLDd
_*CbtQb5
public void run() ^CW{`eBwk
{ naVbcY
while(nStartPos < nEndPos && !bStop) F<J`1 :
{ /&W~:F
q,>4#J[2;s
h_15"rd
try{ _&aPF/
URL url = new URL(sURL); aV#phP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y=Om0=v
httpConnection.setRequestProperty("User-Agent","NetFox"); 2*a5pFkb
String sProperty = "bytes="+nStartPos+"-"; >1hhz
httpConnection.setRequestProperty("RANGE",sProperty); Kiq[PK
Utility.log(sProperty); zoZ10?ojC
pyp0SGCM:
v(=E R%
InputStream input = httpConnection.getInputStream(); qm< mw"]
//logResponseHead(httpConnection); 7KN+ @6!x
k,-0OoCL-!
5A+r^xN
byte[] b = new byte[1024]; ;Q0H7)t:
int nRead; v\D.j4%ij
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y|ErVf4
{ }!N/?A5
nStartPos += fileAccessI.write(b,0,nRead); 2yV^'o)
//if(nThreadID == 1) !vq|*8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >1$Vh=\OI
} RcOfesW o
Rd[^)q4d$w
Q096M 0m
Utility.log("Thread " + nThreadID + " is over!"); )j. .)o
bDownOver = true; *gOUpbtXa
//nPos = fileAccessI.write (b,0,nRead); bWJ&SR>
} q^h/64F
catch(Exception e){e.printStackTrace ();} {RI)I
} _pxurq{
} }8'b}7!
6eb~Z6n&?
a#a n+JY3
//打印回应的头信息 0<+eN8od.
public void logResponseHead(HttpURLConnection con) 3Scc"9]
{ ~~q>]4>
for(int i=1;;i++) (wf3HEb_
{ %Z*N /nU
String header=con.getHeaderFieldKey(i); *!ecb1U5
if(header!=null) bu{dT8g'U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 51;[R8'w
Utility.log(header+" : "+con.getHeaderField(header)); F |aLF{
else B+MnT{
break; <==6fc>s
} Y|buQQ|
} odn3*{c{x
sgRWjrc/
4hzdc] a
public void splitterStop() }ld^zyL
{ nd&i9l
bStop = true; i&{%}==7
} #7@p
z0Z1J8Qq6.
L3A2A
} ]n3!%0]\
J$lfI^^
<h~=d("j
/* r"|.`$:B
**FileAccess.java f~7V<v
*//文件访问(定位，写) }}Z2@}
package NetFox; 4W}mPeEeV
import java.io.*; kK/XYC 0D
h/6^>setz
RT${7=
public class FileAccessI implements Serializable{ i.\ e/9]f
wB&5q!{!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RhC|x,E
RandomAccessFile oSavedFile; $Ggnn#
long nPos; 0T^0)c
sPXjU5uq#
`F3wO!
public FileAccessI() throws IOException cL][sI
{ Ubgn^+AI
this("",0); 7iyx_gyo
} c=zSq%e
(L yKo
Cy)N hgz
public FileAccessI(String sName,long nPos) throws IOException e\O-5hp7
{ Qqx!'fft
oSavedFile = new RandomAccessFile(sName,"rw"); dMCoN8W
this.nPos = nPos; EiG5k.C@
oSavedFile.seek(nPos); `WnsM;1Y"
} ~Z!YB,)bp
x,zYNNx5g
WIuYSt)h
public synchronized int write(byte[] b,int nStart,int nLen) +k~0&lZi
{ ;<_a ,5\Q
int n = -1; (\!?>T[En
try{ H5V>d
oSavedFile.write(b,nStart,nLen); 7mf&`.C np
n = nLen; 3zu6#3^
} Cs y,3XG
catch(IOException e) /'5d0' ,M
{ ^9]iUx
e.printStackTrace (); V1pBKr)v
} s]|tKQGl,
SOn)'!g
_>rM[\|X
return n; ir"t@"Y;o
} G]N3OIw&8
9t6c*|60#n
OM{^F=Ap
} jT}={[9b
I "O^.VC
:8hI3]9
/* &$ "J\vm
**SiteInfoBean.java MIn_?r
*/ G"OP`OMDc
package NetFox; `GdH ,:S>
sZT~5c8
q7f`:P9~
public class SiteInfoBean { C\~}ySQc.e
BgQ/$,
I`H&b& .`
private String sSiteURL; //Site's URL >}%#s`3W1_
private String sFilePath; //Saved File's Path y<6c*e1
private String sFileName; //Saved File's Name ()bQmNqmO=
private int nSplitter; //Count of Splited Downloading File d&raHF*
, ?U)mYhI
7C0xKF
public SiteInfoBean() ]%HxzJ
{//nSplitter的缺省值为5 GWWg3z.o"W
//default value of nSplitter is 5 vxTn
this("","","",5); jwa6`u
} HI 1T
'jfE?ngt
#}+H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (${ #l
{ fmj}NV&ma
sSiteURL= sURL; [n)ak)_/
sFilePath = sPath; Um{) ?1
sFileName = sName; }P0bNY5?%
this.nSplitter = nSpiltter; I`X!M!dB)
L"vrX
+]A,fmI.
} @jm+TW
RQ=$, i`
oI/_WY[t
public String getSSiteURL() "Gp Tmu?
{ (ct1i>g
return sSiteURL; pxgf%P<7
} \efDY[j/
g;'S5w9S
|ugdl|f
public void setSSiteURL(String value) 1C{0 R.
{ oSD=3DQ;
sSiteURL = value; Os-Z_zSl6
} !DFTg4xb
@9| jY1
,HTwEq>-G
public String getSFilePath() +_J@8k
{ 7>y]uT@ar
return sFilePath; fc@<'-VA
} W,6q1
a<q9~QS
v)_c*+6u
public void setSFilePath(String value) @y7KP$t
{ Hq 5#.rZ#
sFilePath = value; /C Xg$%\
} =K}Pfh
Ve%ua]qA
gi,7X\`KQ
public String getSFileName() xaVX@ 3r.3
{ V'=;M[&
return sFileName; ^6kl4:{idE
} &,%n
0SYJ*7lPX
&?bsBqpN
public void setSFileName(String value) xIm2t~io
{ "=s}xAM|A
sFileName = value; Xydx87L/-e
} tqh)yr;
KBtqtE'(L
BedL `[,
public int getNSplitter() 9`/e=RL
{ L;")C,CwQ
return nSplitter; 1q!k#Cliu
} I\6C0x
k 6[
WuY#Kx~2
public void setNSplitter(int nCount) HN NeH;L
{ Sy <E@1
nSplitter = nCount; ASoBa&vX
} =<HekiYM
} Fz(;Eo3
Q" h]p
Z72%Bv
/* ,^c-}`!K
**Utility.java Hif|z[0$
*/ qbq2Bi'a
package NetFox; &2 Yo
3lWGa7<4Z
>x6\A7
public class Utility { %IVM1
4K:Aqqhds
oe^JDb#
public Utility() GPh;r7xg6
{ F%y#)53g
OCdX'HN5Y
0N!rIz
} a] c03$fK
'j'6x'[>]
//线程睡眠 >V)#y$Z
public static void sleep(int nSecond) nt>3i! l
{ YR\(*LJL
try{ Cd^1E]O0{
Thread.sleep(nSecond); x4kQGe(
} qmnl
catch(Exception e) ]]r;}$
{ `dX0F=Ag?
e.printStackTrace (); XLiwE$:t%
} Xbx=h^S
} w]xr ~D+
F#9^RA)9
//日志 H'$H@Kn]-
public static void log(String sMsg) ;8MQ'#
{ GJU(1%-
System.err.println(sMsg); =YO<.(Lu
} a6:hH@,
nvQX)Xf
wU'+4N".
public static void log(int sMsg) cY!Pv
{ VPO~veQ
System.err.println(sMsg); -8"K|ev
} @`B_Q v@
} >u0XV"g$
{ **W7\h
fbdpDVmpU
/* >@G"*le*)
**TestMethod.java #$U/*~m $
*/ LrdED[Z
package NetFox; ,qB@agjvo<
4k{xo~+%,
v`Y{.>[H[
public class TestMethod { ^"iL|3d
-e"kJd&V
`DGI|3
public TestMethod() @+Nf@LJ
{ ///xx/weblogic60b2_win.exe C %j%>X`
try{ pIpdVKen
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >ZgV8X:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t5 ^hZZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); D\J.6W
fileFetch.start(); eq"Xwq*
} NTK9`#SA
catch(Exception e){e.printStackTrace ();} `{IL.9M!f
3 Sf':N`u
LtUw
} GKUjtPu
*(wxNsK
:T@} CJ
public static void main(String[] args) 1jBIi
{ eMn'z]M&]
new TestMethod(); ]i1OssV~>
} QAl4w)F
} 2"}Vfy
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