http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); #@^mA{Dt5
} B*c@w~E
for(int i=0;i<nEndPos.length-1;i++) [.[|rnil
{ :IB@@5r1
nEndPos = nStartPos[i+1]; a|5^4 J\%
} r}%2;!T
nEndPos[nEndPos.length-1] = nFileLength; O S%
} KO''B or
} 'Io2",~ M
2]i>kV/,0
552U~t
//启动子线程 Z+EN]02|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !8ch&cr)o+
for(int i=0;i<nStartPos.length;i++) eX0ASI9
{ 8-.jf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F&[MyXU4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Mb +
nStartPos,nEndPos,i); Hp}dm93T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g6V>_|
fileSplitterFetch.start(); 3`%U)gCT5
} H-ewO8@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^.:dT?@R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G1z0q3< B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 079mn/8;
nEndPos = " + nFileLength); tg|7\Z7i
// fileSplitterFetch[nPos.length-1].start(); j7u\.xu9
z!> H^v
16Gp nb
//等待子线程结束 FKpyD
//int count = 0; >/eV4ma"
//是否结束while循环 7!r)[2l
boolean breakWhile = false; =T3O;i
c!20((2|I
uu`G<n
while(!bStop) 9u%S<F"
{ DI,8y"!5
write_nPos(); s^6"qhTa
Utility.sleep(500); S#g=;hD
breakWhile = true; s;NPY
x=jS=3$8
2,bLEhu
for(int i=0;i<nStartPos.length;i++) %*Aq%,.={
{ S(MVL!Lm
if(!fileSplitterFetch.bDownOver) |o0?u:
{ %hO/2u
breakWhile = false; s?-J`k~q
break; C;BC@OE
} W2-1oS~ma
} m c q!_#{y
if(breakWhile) qQ=\R1l
break; =bDy :yY}
U)B^R
2C@s-`b
//count++; 10`]&v]T
//if(count>4) %g+*.8;"b
// siteStop(); J3P)oM[
} v$_YZm{!<
pipO,n
fBZAO
System.err.println("文件下载结束！"); E%tGwbi7
} ER4j=O#
catch(Exception e){e.printStackTrace ();} "oc&uj
} {T2=bK~
OqNtTk+
@GrQ/F7
//获得文件长度 g[ dI%
public long getFileSize() nJ{vO{N
{ !caY
int nFileLength = -1; ?r"QJa>
try{ FvTc{"w /
URL url = new URL(siteInfoBean.getSSiteURL()); ,Q>RtV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $lYy`OuC
httpConnection.setRequestProperty("User-Agent","NetFox"); \n}@}E L
t7].33%\
.W/#$s|X\
int responseCode=httpConnection.getResponseCode(); ay-M.J
if(responseCode>=400) =k+nC)e
{ ~n<U8cm O
processErrorCode(responseCode); 7>sNjOt@M
return -2; //-2 represent access is error /%4wm?(eA
} -<MA\iSP
M}cgVMW
07FS|>DM'Z
String sHeader; riuG,$EX
E]<Ce;Vj
!Ic{lB
for(int i=1;;i++) QhqXd
{ B<}0r4T}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oI2YJ2?Je8
//Utility.log(in.readLine()); t<%S_J\
sHeader=httpConnection.getHeaderFieldKey(i); m.|__L
if(sHeader!=null) Cvk n2T
{ U|2*.''+Q
if(sHeader.equals("Content-Length")) F[HMX4
{ 1B#Z<p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KOqp@K$
break; Rfuq(DwD6
} <.6bni )
} |4lrVYG^K
else 6%nKrK
break; Frxim
} SmR"gu
} aOWfu^&H:
catch(IOException e){e.printStackTrace ();} 0w24lVR.
catch(Exception e){e.printStackTrace ();} D6wg^'Q:
|#x]FNg
&t0toEj
Utility.log(nFileLength); T+9#&
n@"h^-
/ZcqKC
return nFileLength; GLIe8T*ht
} QL{{GQ_dn
XNm%O
`VB]4i}u
//保存下载信息（文件指针位置） fsr0E=nV
private void write_nPos() &-s/F`
{ icnc5G
try{ _#2AdhCu
output = new DataOutputStream(new FileOutputStream(tmpFile)); l[)ZEEP
output.writeInt(nStartPos.length); P{{pp<tX*&
for(int i=0;i<nStartPos.length;i++) x9&{@ ?o
{ liuF;*
// output.writeLong(nPos); e?"XMY
output.writeLong(fileSplitterFetch.nStartPos); k&kx%skz
output.writeLong(fileSplitterFetch.nEndPos); nKP[U=ac
} =@UgCu>=
output.close(); E}*
} JkiMrpkuk
catch(IOException e){e.printStackTrace ();} pP`KI'aUN
catch(Exception e){e.printStackTrace ();} n%"0%A
} HRPNZ!B
E(l'\q'.
/M.@dW7 w
//读取保存的下载信息（文件指针位置） tCw.wDq3=
private void read_nPos() ,2I8,MOg
{ ebuR-9
try{ kN99(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z 5T_
int nCount = input.readInt(); svBT~P0x
nStartPos = new long[nCount]; tBZ&h` V
nEndPos = new long[nCount]; rTR4j>Ua~
for(int i=0;i<nStartPos.length;i++) h.`U)6*?&N
{ ?\eq!bu
nStartPos = input.readLong(); o,#[Se*n
nEndPos = input.readLong(); }.uB6&!:
} H,F/u&O
input.close(); *t,J4c
} .Y?/J,Ch
catch(IOException e){e.printStackTrace ();} &?-LL{W{
catch(Exception e){e.printStackTrace ();} Ot]Y/;K
} :4ndU:.L
\;b)qB
h7EKb-@
private void processErrorCode(int nErrorCode) -RSPYQjz
{ m _0D^e7#
System.err.println("Error Code : " + nErrorCode); jf_0IE
} N<xf=a+j
UP@a ?w
X CjYm
//停止文件下载 }P5zf$
public void siteStop() '}`|QJ
{ Pmj]"7Vd[
bStop = true; Y[A`r0
for(int i=0;i<nStartPos.length;i++) Llf |fayq
fileSplitterFetch.splitterStop(); d" "GG/
31w9$H N
&*I\~;1
} :?Xd&u0){
} =ZsM[wd
//负责部分文件的抓取 3lyk/',
**FileSplitterFetch.java FyZa1%Tv@
*/ P(_wT:8C?
package NetFox; Z=ayVsJ3
uc% &g
CvCk#:@HM
import java.io.*; 6AZJ,Q\E@
import java.net.*; RP2MtP"M
idm!6]
C] <K s
public class FileSplitterFetch extends Thread { 0hKF)b
\iQD\=o
+F &,,s"&
String sURL; //File URL q;T3bxp+
long nStartPos; //File Snippet Start Position RLypWjMx$
long nEndPos; //File Snippet End Position U&fOsx?"
int nThreadID; //Thread's ID 05(lh<C
boolean bDownOver = false; //Downing is over C+r<DC3
boolean bStop = false; //Stop identical 5Rv6+d
FileAccessI fileAccessI = null; //File Access interface Kilq Jg1%C
73$^y)AvY
})V9d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Gy9+-7"V
{ la ~T)U7
this.sURL = sURL; |kvom 4T
this.nStartPos = nStart; ta>:iQa
this.nEndPos = nEnd; G<kslTPyq
nThreadID = id; 10v4k<xb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Azx4+`!-
} })OgsBk
N[%^0T$
r5qp[Ss3F
public void run() ]8(_{@/
{ )bZS0f-
while(nStartPos < nEndPos && !bStop) iH& Izv
{ j2T Z`Z?a^
>9{Gdq[gyr
g{@q
try{ _B`'1tNx
URL url = new URL(sURL); j]EeL=H<P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G#ov2
httpConnection.setRequestProperty("User-Agent","NetFox"); |3f?1:"Z
String sProperty = "bytes="+nStartPos+"-"; .jRp.U
httpConnection.setRequestProperty("RANGE",sProperty); SxLu<
Utility.log(sProperty); ql5NSQ>{
Z 6^AO=3
fYF\5/_
InputStream input = httpConnection.getInputStream(); dxkq*
//logResponseHead(httpConnection); d\}r.pD
j )6A
F}P+3IaE
byte[] b = new byte[1024]; ahNpHTPa
int nRead; h#9X0u7j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q=lQy
{ EnXNTat})
nStartPos += fileAccessI.write(b,0,nRead); 8 /1 sy.R
//if(nThreadID == 1) w-l:* EV8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [mKPOg-t
} !6:kJL}U
@K; 4'b~
oJJ2y
Utility.log("Thread " + nThreadID + " is over!"); 4QODuyl2H
bDownOver = true; 5LU8QHj3
//nPos = fileAccessI.write (b,0,nRead); (j;s6g0
} VdpwZ
catch(Exception e){e.printStackTrace ();} I/D(gY06<
} v'(p."g
} Lu!o!>b
UU')V
9|v3lGK(
//打印回应的头信息 Jylav:
public void logResponseHead(HttpURLConnection con) 6qQdTp{i
{ <U(wLG'XS
for(int i=1;;i++) (055>D6
{ Coz\fL
String header=con.getHeaderFieldKey(i); };"-6e/9
if(header!=null) K[JbQ30
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vZ[wr@)
Utility.log(header+" : "+con.getHeaderField(header)); }t}y
else 'E FP/(2J
break; k^B<t'
} KECo7i=e
} Hd H,
b_2bg>|;
o NX-vN-
public void splitterStop() LUSBRr8
{ 34S0W]V
bStop = true; ]t$wK
} -?L~\WJAL
/ i[F
!Au'WJfE
} tnL$v2e6q
ASA ]7qyO
?:DeOBAb
/* z2'3P{#s
**FileAccess.java r]JV!'R
*//文件访问(定位，写) oD1rt>k
package NetFox; fS9TDy
import java.io.*; ;7,>2VTm
?wM{NVt#-
M&auA
public class FileAccessI implements Serializable{ (R^X3
#Bu W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *Ae> ,LyE
RandomAccessFile oSavedFile; miWog8j
long nPos; ZSWKVTi
hb@,fgo!Q
7dxTyn=
public FileAccessI() throws IOException C8dC_9
{ B?M&j
this("",0); >~_oSC)E
} 05 56#U&>
E~]37!,\\9
oUSv)G.zb
public FileAccessI(String sName,long nPos) throws IOException (rTn6[*
{ 3Lg)237&j
oSavedFile = new RandomAccessFile(sName,"rw"); &Ul8h,qw
this.nPos = nPos; /i:c!l9
oSavedFile.seek(nPos); $W_sIS0\z
} /O`<?aP%
c+a"sx\
<PMQ$s>KK
public synchronized int write(byte[] b,int nStart,int nLen) RX])#=Cs
{ kH4xP3. i
int n = -1; 5`>%{ o
try{ {wK|C<K
oSavedFile.write(b,nStart,nLen); X0FTD':f
n = nLen; A!GQ4.~%
} 1@}s:
catch(IOException e) H@|h Nn$@
{ 1r9.JS
e.printStackTrace (); m7$t$/g
} Bjc<d,]
_GW,9s^A
cPp<+ ts
return n; @sPuc.
} k`(Cwp{Oc
tS[@3h
HI\V29 a
} 8~!9bg6C
bCfw,V{sce
UlD]!5NO
/* P9yg
**SiteInfoBean.java jt?DogYx
*/ &@U)
package NetFox; l>D!@`><I
wAA9M4
LW#$%}
public class SiteInfoBean { :jHDeF.A
yM PZ}
hanS8
private String sSiteURL; //Site's URL Va-.
private String sFilePath; //Saved File's Path (dnaT-M3
private String sFileName; //Saved File's Name E``\Jre@
private int nSplitter; //Count of Splited Downloading File ir<K"wi(2
8#h~J>u.
^3O`8o
public SiteInfoBean() ]w/%>
{//nSplitter的缺省值为5 \R|qXB $
//default value of nSplitter is 5 w:3CWF4q]
this("","","",5); @.8FVF
} [,TK"
:zK\t5
bH`r=@.:cu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q]rqFP0C
{ LB\+*P6QM
sSiteURL= sURL; [J\! 2\Oo
sFilePath = sPath; s$ZKd
sFileName = sName; *wl&Zzx
this.nSplitter = nSpiltter; XtftG7r9S
bFB.hkTP
I~T~!^}U
} i~ITRi@
EHH+)mlo
'9tV-whw
public String getSSiteURL() Lgrpy
{ r 3FUddF'
return sSiteURL; @$R^-_m
} jn._4TQ*}
U}c05GiQw
9D{p^hd
public void setSSiteURL(String value) zOn%\
{ /|WBk}
sSiteURL = value; I#U)
} JLh{>_Rr
il~A(`+YO
4YyVh.x
public String getSFilePath() |*y'H*
{ PwS7!dzH-
return sFilePath; NxrfRhaU3
} 0I7 r{T
i/j eb*d0
q 1~3T;Il
public void setSFilePath(String value) m/p:W/0L
{ !CUX13/0
sFilePath = value; EeDK ^W8N
} G~{#%i
f19'IH$n{
8^5@J)R8
public String getSFileName() DpvMY94Qh
{ VskdC?yIp
return sFileName; >"<<hjKJ
} _.+2sm
Ybp';8V
[_1K1i"m
public void setSFileName(String value) QRz5eGpW
{ cjc1iciZ
sFileName = value; ;bYLQ
} !b?`TUt
kA{eT
{"hyr/SKd
public int getNSplitter() {LqahO*
{ .Gn-`
return nSplitter; 63T4''bwu
} :0vKt 6>Sp
]<:qMLg
?7\$zn)v#
public void setNSplitter(int nCount) 4C`p`AQqpQ
{ *9|*21
nSplitter = nCount; 8w9?n3z=}
} g%%j"Cz1
} !xz{X?
*s6(1S
K yDPD'
/* YTV|]xpR
**Utility.java i1DJ0xC]
*/ ;\rKkH"K8n
package NetFox; (laVmU?I7
Mo0pN\A}h
ebIRXUF}>
public class Utility { QRlrcauM
*7^w}v+.
z0xw0M+X
public Utility() ?vV&tqnx%
{ 6 u}c543
xL\R-H^c]
Ue!~|:
} n--w-1
,xuA%CF-S
//线程睡眠 r"x/,!_E
public static void sleep(int nSecond) ghDOz 3
{ `m=u2kxY
try{ y({EF~w
Thread.sleep(nSecond); X$9 "dL
} k/.a yLq
catch(Exception e) #6F/:j;
{ H*vd
e.printStackTrace (); d>}R3T
} F8>J(7On
} *."a>?D~
+w9X$<?_
//日志 BiCC72oig
public static void log(String sMsg) /6nj 4.xxc
{ g: ,*Y^T
System.err.println(sMsg); z P=3B%$
} (sL!nRw
Pef$-3aP>E
tP0!TkTo9
public static void log(int sMsg) 4A\>O?\
{ Mt
System.err.println(sMsg); wH0Ks5
} g"|Z1iy|9
} ;SVAar4r
I'a&n}jx
+nm?+F
/* RAi]9`*7
**TestMethod.java drW}w+!
*/ %xhA2
package NetFox; dXewS_7
,e!9WKJ B
y-k]Tr
public class TestMethod { Q|i`s=|
U[WR?J4~LX
K f}h{X
public TestMethod() >TB Rp,;r
{ ///xx/weblogic60b2_win.exe eO?@K$I
try{ +RN|ZG&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Gz@/:dW^vZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5.X`[/]<r
SiteFileFetch fileFetch = new SiteFileFetch(bean); NI33lp$V
fileFetch.start(); HYWKx><
} ~$:=hT1
catch(Exception e){e.printStackTrace ();} bZ_vb? n
{3R?<ET]mt
z57|9$h}w
} *7:HO{P>Y
U1~6o"1H
i\94e{uty[
public static void main(String[] args) ^7$V>|
{ r8Pdk/CW^
new TestMethod(); Q~S3d
} 0DgEOW9H
} 6O# xV:Uc<
点击下载更多相关资料