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)); jF$bCbAUce
} z6IOVQ*r
for(int i=0;i<nEndPos.length-1;i++) _h6j, )
{ <QuIXA
nEndPos = nStartPos[i+1]; V8w7U:K
} 8+f{ /
nEndPos[nEndPos.length-1] = nFileLength; rCK
} %>p[;>jW
} G_m$?0\
]!c59%f=
r5RUgt
//启动子线程 J#>)+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a/\SPXQ/9
for(int i=0;i<nStartPos.length;i++) x5w5xw
{ &nV/XLpG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lQS(\}N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^cUmLzM
nStartPos,nEndPos,i); "h@=O c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #r|qitL3
fileSplitterFetch.start(); R\a6#u3
} <<=.;`(/v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aM7e?.rU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cyMvjzzRN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u1}/SlCp
nEndPos = " + nFileLength); K N Y
// fileSplitterFetch[nPos.length-1].start(); )_&P:;N
%K`th&331
bIWSNNV0F
//等待子线程结束 JpRn)e'Z
//int count = 0; 4Wd H!z
//是否结束while循环 adcH3rV
boolean breakWhile = false; A`B>fI
UF&B7r
/~(T[\E<
while(!bStop) 6%a9%Is!O
{ -Qy@-s $
write_nPos(); ]x1;uE?1J
Utility.sleep(500); &lCOhP#
breakWhile = true; a1>Tz
sSLVR^
P5JE = &M
for(int i=0;i<nStartPos.length;i++) bJ"}-s+Dx
{ :[:*kbWN-
if(!fileSplitterFetch.bDownOver) UVd ^tg
{ `@<~VWe5
breakWhile = false; dc dVB>D
break; &wX568o
} Ia[4P8Z
} \wKnX]xGf
if(breakWhile) $$ 9!4
break; p uZY4}b_
Yu}[RXC(=
'uW&ADp
//count++; Z=m5V(9
//if(count>4) Gw$Y`]ipy
// siteStop(); 4wkmgS
} A-eRL`
!X5LgMw^;
aBd>.]l?
System.err.println("文件下载结束！"); qOTo p-
} j5gL67B
catch(Exception e){e.printStackTrace ();} `Hx JE"/
} _ea|E 8
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+h)1NX;o1
//获得文件长度 U]]ON6Y&F
public long getFileSize() ae#Qeow`
{ S l`F`
int nFileLength = -1; 1)H;}%[
try{ FvJkb!5*e_
URL url = new URL(siteInfoBean.getSSiteURL()); cCuK?3V4K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O@>ZYA%
httpConnection.setRequestProperty("User-Agent","NetFox"); &R))c|>OT&
/M@[ 8
FfX*bqy
int responseCode=httpConnection.getResponseCode(); NI:3hfs
if(responseCode>=400) YO9ofT
{ C"0vMUZ
processErrorCode(responseCode); K8JshFIe
return -2; //-2 represent access is error 5^97#;Q;J"
} ,_UTeW6M
1{<r~
`J$7X
String sHeader; M1q_gHA
#Y0ru9
6u9?
for(int i=1;;i++) Fr_6pEH]}
{ q`|rS6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0iV~MQZ(
//Utility.log(in.readLine()); Ov#G7a"
sHeader=httpConnection.getHeaderFieldKey(i); d}2(G2z^
if(sHeader!=null) 7lx]`u>
{ rhDiIO_
if(sHeader.equals("Content-Length")) 3Ct:AJeg
{ 6 u1|pX8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); goOw.~dZ'
break; -cWGF
} oh7tE$"c
} iOtf7.@
else }OqP`B
break; xnDst9%
} 6@;sOiN+
} ,FwJ0V
catch(IOException e){e.printStackTrace ();} HF<h-gX
catch(Exception e){e.printStackTrace ();} z~th{4#E;
e!ql8wbp
LvCX(yjZ*
Utility.log(nFileLength); v"l8[::
&bigLe
r3+
return nFileLength; (e#f
} .JBTU>1]_n
*LEI@
}"&Ye
//保存下载信息（文件指针位置） 6!C>J#T
private void write_nPos() M0t9`Z9
{ #fDM{f0]R
try{ B%WkM\\!^
output = new DataOutputStream(new FileOutputStream(tmpFile)); lf\^!E:
output.writeInt(nStartPos.length); ; Kh!OBZFo
for(int i=0;i<nStartPos.length;i++) nwVW'M]r
{ 4>Y*owa4
// output.writeLong(nPos); Nj.;mr<
output.writeLong(fileSplitterFetch.nStartPos); l(HxZlHr
output.writeLong(fileSplitterFetch.nEndPos); r&_e3#]*
} Wjli(sT#-
output.close(); $|N\(}R
} ?ph>:M
catch(IOException e){e.printStackTrace ();} MvTp%d.
catch(Exception e){e.printStackTrace ();} x@@bC=iY$
} 6$K@s
3:>hHQi
qJJ},4}
//读取保存的下载信息（文件指针位置） vwzElZ{C:v
private void read_nPos() 89m9iJ=
{ ?z0W1a
try{ yG^pND>_df
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `i!fg\qnK
int nCount = input.readInt(); VONC<wC
nStartPos = new long[nCount]; P5W58WxT'
nEndPos = new long[nCount]; -56gg^Pnr
for(int i=0;i<nStartPos.length;i++) y@r0"cvz9
{ m%b#B>J,n
nStartPos = input.readLong(); $WO{!R
nEndPos = input.readLong(); @SI,V8i
} dsg-;*%
input.close(); /CUBs!
} Bh&dV%'
catch(IOException e){e.printStackTrace ();} a+j"8tHu$
catch(Exception e){e.printStackTrace ();} O"#/>hmv-
} Ed+jSO0
lx7]rkWo|a
e|q~t {=9S
private void processErrorCode(int nErrorCode) B}J0d
{ V{fG~19
System.err.println("Error Code : " + nErrorCode); j@{B 8
} TiR00#b
0es\ j6c
j9X|c7|
//停止文件下载 vnS8N
public void siteStop() tns4e\
{ f@k.4aS
bStop = true; !="8ok+
for(int i=0;i<nStartPos.length;i++) <*9(m
fileSplitterFetch.splitterStop(); bwa*|{R
>uDC!0)R
&}t8O?!
} )iJv?Y\]
} xz~Y %Y|Z
//负责部分文件的抓取 av_ +M;G
**FileSplitterFetch.java z0%tBgqY(
*/ hVl@7B~
package NetFox; vpC?JXz=H
/t*Q"0X5
fYW9Zbov-
import java.io.*; n:f&4uKoG<
import java.net.*; =G !]_d0
l&5Tft
IG:2<G
public class FileSplitterFetch extends Thread { 13 %:3W(
!L<z(dV|(
rs,'vV-2\
String sURL; //File URL hZw8*H^tP
long nStartPos; //File Snippet Start Position 7* [
long nEndPos; //File Snippet End Position N( f0,
int nThreadID; //Thread's ID QP<.~^ao
boolean bDownOver = false; //Downing is over zN=s]b=/
boolean bStop = false; //Stop identical yMC6 Gvp
FileAccessI fileAccessI = null; //File Access interface de;CEm<n
Vt,P.CfdC
zZP/C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5#y_EpL"
{ 13*S<\
this.sURL = sURL; D]5j?X'
this.nStartPos = nStart; aj/+#G2
this.nEndPos = nEnd; d%RH]j4
nThreadID = id; IVVX3RI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >nvnU`\
} +"1-W>HV
J/3$I
skU }BUK6
public void run() ]u:_r)T
{ 64vj6 &L
while(nStartPos < nEndPos && !bStop) Ktu~%)k%
{ a!f71k r
%xKZ"#Z#K
+~=j3U
try{ 4P"XT
URL url = new URL(sURL); itg"dGDk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0g~Cdp
httpConnection.setRequestProperty("User-Agent","NetFox"); 3E0C$vKM
String sProperty = "bytes="+nStartPos+"-"; Z{/GT7 /
httpConnection.setRequestProperty("RANGE",sProperty); x&"P^gh)
Utility.log(sProperty); p/G9P +?
5m;BL+>YE
GDb Vy)&
InputStream input = httpConnection.getInputStream(); g9=_^^Tg
//logResponseHead(httpConnection); \}X[0ct2!
.&`apQD}
QjD=JC+
byte[] b = new byte[1024]; 1f'msy/
int nRead; 6!N2B[9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &C)97E
{ gGN6Yqj0
nStartPos += fileAccessI.write(b,0,nRead); LDYa{w-t
//if(nThreadID == 1) H/Rzs$pnv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z:
} OmK4 \_.
nrX+ '
i r'C(zD=
Utility.log("Thread " + nThreadID + " is over!"); '&2-{Y [!
bDownOver = true; 27}7 n
//nPos = fileAccessI.write (b,0,nRead); %;|dEY
} 6{0MprY
catch(Exception e){e.printStackTrace ();} U9*< dR
} ;lSsy
} 7j29wvSp5
z@ `u$D$n
EWY'E;0@5
//打印回应的头信息 ZE= Yn~XM
public void logResponseHead(HttpURLConnection con) *xITMi
{ Xbrc_V\_
for(int i=1;;i++) WJ LqH<
{ }%<_>b\
String header=con.getHeaderFieldKey(i); 9XhH*tBn7(
if(header!=null) M%RH4%NZ0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &pR 8sySu
Utility.log(header+" : "+con.getHeaderField(header)); TAqX f_
else l?YO!$
break; >YsM'.EFD
} 3g5r}Ug
} 0Wc_m;
2m} bddS
e,Y<$kPV
public void splitterStop() .}uri1k"@k
{ Y9&na&vY?
bStop = true; x34GRe!!
} B|8|f(tsSa
HLdHyK/S
nJ/}b/A{
} rl&.|;5uH;
)4.-6F7U?
^FVmP d*1
/* K4+|K:e
**FileAccess.java 71ab&V il
*//文件访问(定位，写) b'z\|jY
package NetFox; XHOS"o$y
import java.io.*; `%EcQ}Nr
*-uzsq.W
O{Mn\M6
public class FileAccessI implements Serializable{ cMoJHC,!
-t>"s'kv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]0[ot$Da6
RandomAccessFile oSavedFile; %iJ}H6m
long nPos; ls7P$qq
%o{IQ4Lz#
TCIbPsE
public FileAccessI() throws IOException @8+v6z
{ Ta/u&t4
this("",0); *"4l}&
} pU[yr'D.r
{`T^&bk
,nGQVb
public FileAccessI(String sName,long nPos) throws IOException TtKKU4yp
{ ez)Ks`
oSavedFile = new RandomAccessFile(sName,"rw"); RCxwiZaf33
this.nPos = nPos; E H%hL5(
oSavedFile.seek(nPos); td23Z1Elk#
} KmM:V2@A$
NV@$\<
m6]6!_
public synchronized int write(byte[] b,int nStart,int nLen) %DA`.Z9#
{ 9sd}Z,l
int n = -1; l4(FM}0X5}
try{ &-X51O C
oSavedFile.write(b,nStart,nLen); 8V9OMOt!
n = nLen; =dQ/^C_hj
} 8.7q -<Q
catch(IOException e) ;DVg[#
{ :^xNHMp!
e.printStackTrace (); *[BtW56-
} P=\Hi.]%
gW9`k,U
|.&GmP
return n; rKd|s7l
} mZmEE2h
(/!@ -]1
~C>Q+tR8
} _-^mxC|M
[TFp2B~)#
@LDs$"f9=
/* " vc4QH$
**SiteInfoBean.java SBf=d<j 1)
*/ mV)t
package NetFox; hY!>>
ccp9nXv
$J,$_O6
public class SiteInfoBean { J&}1=s
V@TA~'$|
~l{Qz0&
private String sSiteURL; //Site's URL LnN:;h
private String sFilePath; //Saved File's Path B., BP
private String sFileName; //Saved File's Name 3Co1bY:
private int nSplitter; //Count of Splited Downloading File Msfxce
HDKY7Yr
Fp[49
public SiteInfoBean() ]gm3|-EiY
{//nSplitter的缺省值为5 G"kX#k0S
//default value of nSplitter is 5 Q~k|lTf
this("","","",5); : yq2 XE%r
} wL^x9O|`p9
; C(5lD&\5
i[{*(Y$L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >;%QW
{ lA;^c)
sSiteURL= sURL; lN{>.q@V`r
sFilePath = sPath; VGu(HB8n#
sFileName = sName; .;.Zbhm
this.nSplitter = nSpiltter; 5MZv!N
UvB\kIH
]#rV]As
} E}a.qM'
4^4T#f2=e
B4+c3M\$V
public String getSSiteURL() pv&iJ7RN
{ es\ qnq
return sSiteURL; |TkicgeS
} @PhAg
-U?%A:,a|
Br&&#
public void setSSiteURL(String value) 9F6dKPN:
{ zb02\xvf
sSiteURL = value; &jQqlQ j
} a|[f%T<<
3u^wK
#N64ZXz_
public String getSFilePath() :,R>e}lM
{ fQg^^ZXe"
return sFilePath; zxx9)I@?A
} A&%7Z^Pp
SkVah:cF-
DB_oRr[oj
public void setSFilePath(String value) (b&Z\?"
{ W[]|Uu/%
sFilePath = value; [fb9;,x`
} ^^tTA^
c'Z)uquvP
TL7qOA7^X
public String getSFileName() h^`@%g9 S
{ MBKF8b'k
return sFileName; kApDD[N
} 8oRq3"
Pc5C*{C
|E||e10wR
public void setSFileName(String value) d7zZ~n
{ B>\q!dX3
sFileName = value; 0oBAJP
} 0]]OE+9<c
ba ,n/yH
o_kZ
public int getNSplitter() _D8 zKp
{ ;pfN
return nSplitter; FYefn3b
} .'2I9P\!
x;~@T9.
AE`{k-3=%
public void setNSplitter(int nCount) Qm"~XP
{ ;:J"- p
nSplitter = nCount; /7,@q?v
} `_ZbA#R,
} 48G^$T{
BC1smSlJ
$kMe8F_
/* /~fu,2=7
**Utility.java erTly2-SJ
*/ 5xNOIOpDB
package NetFox; a[sdYZ
S==0/
0QrRG$<4X
public class Utility { R3)ccom
AxTFVot
o: > (Tv
public Utility() mRGr+m
{ nKtRJ,>
:fy,%su
_z.CV<
} p}wysVB
j>v8i bS(
//线程睡眠 Txpj#JD
public static void sleep(int nSecond) hg'eSU$J
{ d& v 7l
try{ J<Ki;_=I
Thread.sleep(nSecond); O(.eHZ=
} h2:TbQ
catch(Exception e) qxZf!NX5
{ np}0OX
e.printStackTrace (); Tgi7RAY
} <dBz]W
} vQ$"|8,
1 un!
//日志 1}ifJ~)5S
public static void log(String sMsg) tO"AeZe%|
{ 4U'sBaY!K
System.err.println(sMsg); HyYJ"54
} q_BMZEM
IM2<:N%'
#E<~WpP
public static void log(int sMsg) j{=}?+M
{ I\j-
System.err.println(sMsg); Zny9TP
} {%,4P_m
} ;9J6)zg !n
61HJ%
5,|{|/
/* Fy.!amXu
**TestMethod.java N"~P$B1X
*/ r(n>N0:0Ls
package NetFox; v6=X]Ji{YA
^hT2ed +
V$u:5"qu0
public class TestMethod { I_`NjJ;61
/@DJf\`vM
$h=v;1"
public TestMethod() vJx( lU`Y
{ ///xx/weblogic60b2_win.exe (gcy3BX;
try{ |&bucG=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @|'9nPern
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V^}$f3\B
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6bf!v
fileFetch.start(); ~ySsv
} ZR{YpLFQ
catch(Exception e){e.printStackTrace ();} evVxzU&
8S[bt@v
u`!Dp$P
} ~=otdJ
U2Ky4UFm
%y)hYLOJ
public static void main(String[] args) i.-2 w6
{ CWd &
new TestMethod(); O\%0D.HEz
} v&f\ Jv7
} <fMQ#No
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