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)); Gq]d:-7l
} H+cNX\,
for(int i=0;i<nEndPos.length-1;i++) `Q9+k<
{ g#W_S?
nEndPos = nStartPos[i+1]; T{-2fp8r[
} 3eg5oAZ)G8
nEndPos[nEndPos.length-1] = nFileLength; ^Omfe
} |f NMs
} |Cf mcz(56
=,Ttw>
-i_En^Fi
//启动子线程 ~b8a^6:R"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lfy7w|
for(int i=0;i<nStartPos.length;i++) AQ@v>wr}
{ NJ$e6$g)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), koH4~m{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %D^bahf
nStartPos,nEndPos,i); &`@M8-m#F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /4C`k=>
fileSplitterFetch.start(); %ejeyc
} 3Xdn62[&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ="B n=>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .5g}rxO8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `$-lL"
nEndPos = " + nFileLength); sb'p-Mj
// fileSplitterFetch[nPos.length-1].start(); aJ2H.E
wD=am
R{<Y4C2~
//等待子线程结束 2z-$zB<vyw
//int count = 0; %c1FwAC
//是否结束while循环 z~.9@[LG]
boolean breakWhile = false; FaWl,}]
37KU~9-A
T}2:.Hk:N
while(!bStop) 7!- \L7<
{ $-w5o`e
write_nPos(); eU~?p|Np
Utility.sleep(500); ve%l({
breakWhile = true; SOI)/u
&"AQ;%&N
^Fp=y,D
for(int i=0;i<nStartPos.length;i++) ,o)4p\nV
{ VR v02m5
if(!fileSplitterFetch.bDownOver) D-iUN
{ lJj&kVHb
breakWhile = false; MOLO3?H(
break; #HDesen
} !Mil?^
} tw86:kYEz
if(breakWhile) S.]MOB dt
break; q u:To7
%Qd3BZ
ZeTL$E[E}
//count++; -aN":?8(G
//if(count>4) irmwc'n]
// siteStop(); 3k{c$x}
} ._ih$=
^^ j/
_3U|2(E
System.err.println("文件下载结束！"); l4Y1(
} "7?t)FOo
catch(Exception e){e.printStackTrace ();} xSOoIsL[
} 2H>aC wfX
t 2G1[j!
u#VweXyU
//获得文件长度 8GW ut=D
public long getFileSize() D1! {S7
{ 1t%<5O;R
int nFileLength = -1; wQw-:f-
try{ `uhL61cMp
URL url = new URL(siteInfoBean.getSSiteURL()); .$^wy3:F"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CLktNR(45
httpConnection.setRequestProperty("User-Agent","NetFox"); c85O_J
r_=p,#}#
.m!s". ?[
int responseCode=httpConnection.getResponseCode(); ?N2X)Y@yi
if(responseCode>=400) @>CG3`?}
{ c&A]pLn+x
processErrorCode(responseCode); s+N^PX3
return -2; //-2 represent access is error dv[\.T`LY
} uegb;m
:Lc3a$qtx5
F_ _H(}d
String sHeader; mf~Lzp
X,&xhSzg?
-sx-7LKi
for(int i=1;;i++) VlV)$z_
{ excrXx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tPzM7 n|
//Utility.log(in.readLine()); bCt_yR
sHeader=httpConnection.getHeaderFieldKey(i); w0$R`MOR+
if(sHeader!=null) w@2~`<Hk'"
{ #B\B(y
if(sHeader.equals("Content-Length")) j^rYFS w:Q
{ F;X"3F.!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %p}qO^%M
break; ha5 bD%
} |9x%gUm
} Ef-a4Pi
else BQuRHi IV
break; f{f_g8f[
} -t%L#1k
} CR.bMF}
catch(IOException e){e.printStackTrace ();} 0|GpZuGO9
catch(Exception e){e.printStackTrace ();} a2[8wv1
$xQ"PJ2
srvYAAE
Utility.log(nFileLength); | [p68v>
"zXGp7Q'#
OM1*Iy
return nFileLength; m^5s>hUl
} *|@+rbjVC
|zT%$
*WD;C0?z
//保存下载信息（文件指针位置） ,v|CombIc.
private void write_nPos() v)%[
{ [Yn;G7cK
try{ N*HH,m&
output = new DataOutputStream(new FileOutputStream(tmpFile)); u1wg C#
output.writeInt(nStartPos.length); Ko]QCLL
for(int i=0;i<nStartPos.length;i++) 8>2&h
{ `~0P[>|+
// output.writeLong(nPos); zU=YNrn
output.writeLong(fileSplitterFetch.nStartPos); l#p}{
output.writeLong(fileSplitterFetch.nEndPos); KQ-,W8Q5
} p|b+I"M
output.close(); <r0.ppgY
} ~@[(U!G
catch(IOException e){e.printStackTrace ();} 9=H}yiJz
catch(Exception e){e.printStackTrace ();} F [r|Y-c]
} _`slkwP.
d\\r_bGW
Ck:#1-t8{
//读取保存的下载信息（文件指针位置） ?VUgwP_=
private void read_nPos() ,9F*96
{ uAc@ Z-
try{ IPwj_jvw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZK%Kgk[\:~
int nCount = input.readInt(); QCVsVG!sN
nStartPos = new long[nCount]; ,I/2.Q})[
nEndPos = new long[nCount]; <g] ou YHZ
for(int i=0;i<nStartPos.length;i++) lt&$8jh
{ OTnu{<.a
nStartPos = input.readLong(); %3ou^mcj
nEndPos = input.readLong(); _E3U.mV
} 0S%tsXt+
input.close(); {qJHL;mP:8
} Sb'N];
catch(IOException e){e.printStackTrace ();} ULV)0SB
catch(Exception e){e.printStackTrace ();} G`9cd\^
} Cc@=?
]d[Rf$>vu0
#4Dn@Gqh.Y
private void processErrorCode(int nErrorCode) |if~i;VKL
{ w:ORmR.p
System.err.println("Error Code : " + nErrorCode); bl$+8!~
} '.=Wk^,Ua
I93 ~8wQ
W^5<XX,ON
//停止文件下载 X\o/i\ C}
public void siteStop() -J-3_9I
{ }DJ|9D^yf
bStop = true; 0m]~J_
for(int i=0;i<nStartPos.length;i++) A*G )CG
fileSplitterFetch.splitterStop(); Lhl$w'r
cxAViWsf
MFf05\aDu
} cWgbd^J
} ?SB[lbU
//负责部分文件的抓取 $&ex\_W
**FileSplitterFetch.java sI^@A=.@
*/ $,8CH)w
package NetFox; R;0W+!fE
ZMdM_i?
oq=?i%'>
import java.io.*; sKe9at^E]>
import java.net.*; `Ev A\f
NFrNm'v
A2}Z *U(;
public class FileSplitterFetch extends Thread { fBHkLRFH
fR+Ov8PCq
6V.awg,
String sURL; //File URL MV Hz$hyB
long nStartPos; //File Snippet Start Position l81&[
long nEndPos; //File Snippet End Position 6(ka"Vu~
int nThreadID; //Thread's ID &>&dhdTQ
boolean bDownOver = false; //Downing is over R59e&
boolean bStop = false; //Stop identical g4~X#}:z$O
FileAccessI fileAccessI = null; //File Access interface VQ1?Db(_2
54`bE$:+
&:;/]cwj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H arFo
{ 3X88x-3
this.sURL = sURL; *,O :>Z5I
this.nStartPos = nStart; +O;OSZ
this.nEndPos = nEnd; TSc~$Q]
nThreadID = id; }}kS~ w-#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A6@+gP<
} C ffTv
UgF)J
%Nwyx;>9^K
public void run() )![f\!'PI
{ o8~f
while(nStartPos < nEndPos && !bStop) I ybl;u
{ &*jxI[
[_g#x(=
1TK #eU
try{ fK)ZJ_?w,@
URL url = new URL(sURL); ()+jrrK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c,6<7
httpConnection.setRequestProperty("User-Agent","NetFox"); sh',"S#=@
String sProperty = "bytes="+nStartPos+"-"; L#t-KLJ
httpConnection.setRequestProperty("RANGE",sProperty); 2 ||KP|5@
Utility.log(sProperty); R-g>W
M!xm1-,[
(hhdbf
InputStream input = httpConnection.getInputStream(); 5@w'_#!)
//logResponseHead(httpConnection); BxSk%$J
C5:dO\?O
hW0,5>[7%
byte[] b = new byte[1024]; Ff)~clIK '
int nRead; adRNrt*!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r6O7&Me<
{ "ay,Lr
nStartPos += fileAccessI.write(b,0,nRead); e.3sAUHZ-
//if(nThreadID == 1) 5~`|)~FA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IQ(]66c,
} $Nt=gSWw5
#Qtg\X
+Op%,,Db
Utility.log("Thread " + nThreadID + " is over!"); >)AE|j`
bDownOver = true; /tId#/Y
//nPos = fileAccessI.write (b,0,nRead); beN>5coP%A
} "6`)vgI~
catch(Exception e){e.printStackTrace ();} wu&|~@_s@
} 'T&=$9g7
} ? e9XVQ*
+WV_`Rx#
Ux%\Y.PPI
//打印回应的头信息 ^'C,WZt
public void logResponseHead(HttpURLConnection con) o+if%3
{ 4e(9@OLP
for(int i=1;;i++) ;qMnO_E
{ eI/\I:G{f
String header=con.getHeaderFieldKey(i); Rk437vQD,
if(header!=null) \dp9@y[^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yZj}EBa
Utility.log(header+" : "+con.getHeaderField(header)); ;qT!fuN;
else (!XYH@Mz<w
break; JR? )SGB
} i(&6ys5
} j{7ilo(i
C]\^B6l<
H3/Y
public void splitterStop() RAD4q"}k
{ X-G~/n-x
bStop = true; ])$."g
} v)C:E9!|
={mPg+Ei'
(IoPU+1b
} y:hCBgc;`c
|`q)/ 08b
% L %1g
/* iS:PRa1
**FileAccess.java rr07\;
*//文件访问(定位，写) FkJ>]k
package NetFox; 0w'y#U)&8
import java.io.*; xu_XX#9?b
U'h[{ek
_ RT"1"r
public class FileAccessI implements Serializable{ JucxhjV#,
!q=Q~ea
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P$(iB.&
RandomAccessFile oSavedFile; [c KI0
long nPos; f)AW!/
}]39 iK`w
v8'`gY
public FileAccessI() throws IOException y3@x*_K8
{ jOm&yX
this("",0); mP5d!+[8
} Ch \ed|u
{'c%#\
WDH[kJ
public FileAccessI(String sName,long nPos) throws IOException #8Id:56
{ z!1/_]WJ,
oSavedFile = new RandomAccessFile(sName,"rw"); E-tNB{r@
this.nPos = nPos; +Qi52OG
oSavedFile.seek(nPos); @8Q+=abz
} +SuUI-.
ku[=QsMv
X>@.-{6T
public synchronized int write(byte[] b,int nStart,int nLen) o trTrh
{ gGiV1jN_
int n = -1; #*>7X>,J
try{ @k:f}-t
oSavedFile.write(b,nStart,nLen); :AqnWy
n = nLen; 1<qVN'[
} xo)?XFM2
catch(IOException e) 1n"+~N^\
{ .2{C29g
e.printStackTrace (); V=l Q}sBY
} Lm*LJ_+ B
53u.pc
kq1M<lk
return n; |q!2i
} N5w]2xz!
)q]j?Z.
G|PIH#
} $Op/5j
HDW\S#
1:;&wf
/* WJFTy+bD
**SiteInfoBean.java qq9tBCk
*/ RP@idz
package NetFox; t1RwB23
8#Z\}gGz
%dk$K!5D0
public class SiteInfoBean { ^qzT5W\@
MlC-Aad(
K`_E>k
private String sSiteURL; //Site's URL gH{\y5%rO
private String sFilePath; //Saved File's Path [>Kxm
private String sFileName; //Saved File's Name zk 'e6
private int nSplitter; //Count of Splited Downloading File 7dg 5HH
nxh/&%
C@?e`=9(
public SiteInfoBean() %`T^qh_dE
{//nSplitter的缺省值为5 h&)vdCCk
//default value of nSplitter is 5 :jKXKY+T
this("","","",5); z`r4edk3
} *}iT6OJ
%CE@}
o2e h)rtB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ko]h r
{ tv=FFfQ
sSiteURL= sURL; {}_Oo%IVGK
sFilePath = sPath; n,Mw# r?y
sFileName = sName; k}0
this.nSplitter = nSpiltter; eUw;!Du
(zLIv9$
q!oZ; $
} 4#7@KhK}
g`8 mh&u%
~{7NTW
public String getSSiteURL() 2|NyAtPb5
{ k;:u| s8NS
return sSiteURL; 36Z`.E>~L
} ^nm!NL{z^
Boj{+rE0
owY_cDzrH
public void setSSiteURL(String value) \7tvNa,C
{ }9Dv\"t5
sSiteURL = value; {FmFu$z+[
} u/:Sf*;?
"vRqtEBO@
gMK3o8B/
public String getSFilePath() #/v_h6$
{ Y)5uK:)^
return sFilePath; rnBeL _8C
} 4a\+o]
]jY)M<:J4
n]{}C.C=
public void setSFilePath(String value) N8(x),
{ .Zt/e>K&
sFilePath = value; 0JRBNh
} v*]Xur6e}
YK+Z0ry
.6/p4OR|
public String getSFileName() |2&mvjk@H
{ gLxyRbVI
return sFileName; hE#8_34%s
} x w83K
WI4_4
S"A_TH
public void setSFileName(String value) C`_D{r
{ 5F+ f'~
sFileName = value; !<PTsk F
} Z6AU%3]
L8K3&[l%
l3|>*szX
public int getNSplitter() MmX[xk
{ R]sjG<
return nSplitter; m1; <T@
} k 5r*?Os
v;qL?_:=c
vHe.+XY
public void setNSplitter(int nCount) F"#*8P
{ WIlS^?5I<
nSplitter = nCount; J& SuUh<
} z}N^`_ *
} ~4` ec
2}Plr{s9
AX Jj"hN
/* *ik)>c_
**Utility.java B=/=U7T
*/ &>4$ [m>n
package NetFox; 9U1!"/F
`l0icfy
GeTCN
public class Utility { +hhbp'%
I%*Zj,>
IX3yNTW"L
public Utility() um;U;%?Q
{ pG=zGx4
s"F,=]HQ!G
oqo8{hrdHk
} )4~XZt1r
Jpnp'
//线程睡眠 .@Sh,^v
public static void sleep(int nSecond) vjWgR9 4/{
{ / ^M3-5@Q
try{ XxQ2g&USk
Thread.sleep(nSecond); =,Um;hU3r
} a#**96Av
catch(Exception e) #^w 1!xXD
{ +mPB?5
e.printStackTrace (); }slEkpk?]
} '~=xP
} ky"7 ^
fb=vO U
//日志 l{{ #tW
public static void log(String sMsg) X KeK;+
{ EqwA8?M
System.err.println(sMsg); OU=IV;V{
} = $Yk8,
OVK(:{PwS
C>-"*Lt
public static void log(int sMsg) ~a)20
{ r|$g((g
System.err.println(sMsg); "d*
} dQo$^?
} > _) a7%
\05C'z3]
KA[Su0
/* ~z"->.u
**TestMethod.java x6P^IkL:
*/ 2!`Z3>Oa
package NetFox; A[Xw|9
cW>`Z:6{K
:9>nY
public class TestMethod { F<1'M#bl
Ho9*y3]
~_6rD`2cJ
public TestMethod() yZ6X$I:C
{ ///xx/weblogic60b2_win.exe PSvRO%&
try{ nI` 1@vB&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @72G*u\Wz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0(.C f.B~
SiteFileFetch fileFetch = new SiteFileFetch(bean); of<OOh%3
fileFetch.start(); zy5bDL -
} }0*7bb
catch(Exception e){e.printStackTrace ();} a#@opUn-
|LhuZ_;1xo
V6o,}o&-
} R'_[RHFC
}zLE*b,
z}|'&O*.F
public static void main(String[] args) }:Akpm
{ WV5R$IqY
new TestMethod(); HKf3eC
} ? -tw*2+
} {K}+$jzGVt
点击下载更多相关资料