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)); #5=Yg5
} V)C4 sG
for(int i=0;i<nEndPos.length-1;i++) \&"gCv#
{ M"1}"ex#
nEndPos = nStartPos[i+1]; YiB^m
} 6>X7JMRY
nEndPos[nEndPos.length-1] = nFileLength; >q"mI6F
} E]i3E[T
} `!
AYfW}V"
'4ftclzL
//启动子线程 j$,:cN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $O?&!8);,
for(int i=0;i<nStartPos.length;i++) 3D(/k%;)
{ R8sj>.I9j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KHI-m9(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4uwI=UUB
nStartPos,nEndPos,i); DFcgUEq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EH=[!iW;
fileSplitterFetch.start(); X6kCYTJYF
} 4Un(}P'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S&q@M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Mnc9l ^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", JN,4#,
nEndPos = " + nFileLength); ^cn%]X#.
// fileSplitterFetch[nPos.length-1].start(); Il`35~a
=# <!s!
JgEPzHgx
//等待子线程结束 ">@]{e*
//int count = 0; K)QMxn
//是否结束while循环 0NL~2Qf_4
boolean breakWhile = false; C|*U)#3:F
s#hIzt
I r]#u]Ap
while(!bStop) OWx-I\:
{ j]Kpwf<NS
write_nPos(); {CdQ)|
Utility.sleep(500); Zi/tax9C
breakWhile = true; u$O` \=
~=67#&(R
#rD0`[pz
for(int i=0;i<nStartPos.length;i++) B<zoa=
{ OX-t#R`
if(!fileSplitterFetch.bDownOver) P{-j^'y
{ 4YX/=
breakWhile = false; /H3z~PBa
break; 1DLAfsLlj
} 6V-u<FJ
} *t=8^q(K[
if(breakWhile) LDc?/ Z1
break; ~.7/o0'+
)31{.c/
/N'0@q
//count++; iI.pxo s
//if(count>4) |qm_ESzl
// siteStop(); Xt} 4B#
} H{hd1
UTwXN |'|
t/%{R.1MN
System.err.println("文件下载结束！"); ,a 2(h
} <;kcy :s
catch(Exception e){e.printStackTrace ();} Sqn|
} w2X0.2)P2
&X3G;x2;
2i0 .x
//获得文件长度 3']a1\sy^
public long getFileSize() <$z6:4uN_
{ W>#[a %R
int nFileLength = -1; # RoJD:9
try{ NVnId p
URL url = new URL(siteInfoBean.getSSiteURL()); L!;"73,&(8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r+:]lO
httpConnection.setRequestProperty("User-Agent","NetFox"); C GN=kQ
f |%II,!3
$|"Y|3&X
int responseCode=httpConnection.getResponseCode(); ZNDn! Sj
if(responseCode>=400) +}VaQ8ti4
{ OCW0$V6;D-
processErrorCode(responseCode); Ah2*7@U
return -2; //-2 represent access is error tq$L* ++O
} %plu]^Vy
X8 $Y2?<
+P! ibHfP
String sHeader; MpK3+4UMa
ES}V\k*}
2]of4
for(int i=1;;i++) t|PQ4g<
{ ~7=eHU.@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yE&WGpT
//Utility.log(in.readLine()); -.@dA'j[
sHeader=httpConnection.getHeaderFieldKey(i); /PZx['g
if(sHeader!=null) Zh
{ t]IHQ8
if(sHeader.equals("Content-Length")) y`,;m#frT
{ jFDVd;#CS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D~ogq]
break; mO=A50_&,Q
} O*7vmPy
} %g_)_ ~
else 8KyRD1 (-R
break; _jb'HP
} J5TT+FQ
} a`e'HQ
catch(IOException e){e.printStackTrace ();} Wu~cy}\
catch(Exception e){e.printStackTrace ();} K<rv|bJ
;A6%YY
,xw1B-dx
Utility.log(nFileLength); Tbp;xv_qo
v!`:{)2C
&HQ_e$1
return nFileLength; $PstEL
} ?:tk8Kgf
gc\/A\F<
<78*-Ob
//保存下载信息（文件指针位置） 5jq @ nq6
private void write_nPos() kzk8b?rOA
{ z+Guu8
try{ J`]9n>G
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^sKdN-{
output.writeInt(nStartPos.length); (_%l[:o6
for(int i=0;i<nStartPos.length;i++) s\zY^(v4
{ 3,'LW}
// output.writeLong(nPos); qRSoF04!R
output.writeLong(fileSplitterFetch.nStartPos); N~uc%wOA
output.writeLong(fileSplitterFetch.nEndPos); S zNZY&8 f
} Bs`mzA54
output.close(); ?edf$-"z/
} p*j>s\
catch(IOException e){e.printStackTrace ();} 0q4PhxR`e
catch(Exception e){e.printStackTrace ();} 0q28Ulv9
} *sQ.y {
GrUpATIx
P{LS +.
//读取保存的下载信息（文件指针位置） *knN?`(x
private void read_nPos() 3$?nzKTW\
{ -{}(U
try{ ]=o1to-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L+mE&
int nCount = input.readInt(); 6FYL},.R
nStartPos = new long[nCount]; &OlX CxH
nEndPos = new long[nCount]; /lC,5y
for(int i=0;i<nStartPos.length;i++) /mA\)TL|]
{ -^)<FY\
nStartPos = input.readLong(); <&^[?FdAa
nEndPos = input.readLong(); Im?/#tX
} k8\KCKql
input.close(); 3@nIoN'z
} Q<NQ9lX
catch(IOException e){e.printStackTrace ();} ]4ck)zlv
catch(Exception e){e.printStackTrace ();} x<`^4|<
} lVuBo&
b<!' WpY-
a@Vk(3Rx_
private void processErrorCode(int nErrorCode) vz(=3C[
{ /!JxiGn
System.err.println("Error Code : " + nErrorCode); sSf;j,7V
} 9OFH6-;6`\
&.(iS
LF`]=.Q
//停止文件下载 JMk2OK{0
public void siteStop() 8[.&ca/[
{ dt@~8kS
bStop = true; NT2XG&$W>
for(int i=0;i<nStartPos.length;i++) kh@O_Q`j
fileSplitterFetch.splitterStop(); s2(7z9jR
?2_h.
=;GmLi3A
} q %j8Js
} {Q[ G/=mx
//负责部分文件的抓取 :f:&B8
**FileSplitterFetch.java lI%RdA[
*/ Wy\^}
package NetFox; BL~#-Mm<|l
C=CZtjUt
#D#kw*c
import java.io.*; C?k\5AzT
import java.net.*; amq,^
<& 3[|Ca
[ #ih o(/
public class FileSplitterFetch extends Thread { fN@ZJ~F%j
P*i'uN
<2oMk#Ng^
String sURL; //File URL & kVa*O
long nStartPos; //File Snippet Start Position Qn|8Ic` *
long nEndPos; //File Snippet End Position ~Ad2L*5S
int nThreadID; //Thread's ID !4`:(G59
boolean bDownOver = false; //Downing is over }z#M!~
boolean bStop = false; //Stop identical Q>$lf.)
FileAccessI fileAccessI = null; //File Access interface 1ni72iz\
urE7ZKdI
H5#]MOAP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R|^bZf^
{ 8KN3|)
this.sURL = sURL; QgKR=GR6
this.nStartPos = nStart; (&87 zk
this.nEndPos = nEnd; lxCAZa\
nThreadID = id; g-jg;Ri
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oOc-1C y
} dl3;A_ 2
+*xc4
r`"T{o\e
public void run() %sPze]
{ wd32q7lGo1
while(nStartPos < nEndPos && !bStop) kGs\"zZM
{ N@Oe[X8
AbhR*
{qlcTc
try{ }ng?Ar[
URL url = new URL(sURL); T`pDjT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `&.qHw)
httpConnection.setRequestProperty("User-Agent","NetFox"); ?-%(K^y4r
String sProperty = "bytes="+nStartPos+"-"; 3UmkFK<
httpConnection.setRequestProperty("RANGE",sProperty); "wcw`TsK
Utility.log(sProperty); 3s|:7
D"-Wo}"8O'
D5oYcGc
InputStream input = httpConnection.getInputStream(); 9BpxbU+L;
//logResponseHead(httpConnection); /F9Dg<#a
j!NXNuy:
g\q4-
byte[] b = new byte[1024]; <wb6)U.
int nRead; -"S94<Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0:71Xm
{ 0:n"A,-p
nStartPos += fileAccessI.write(b,0,nRead); &;pM<h
//if(nThreadID == 1) R2?s NlF
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )iiaT~ ]
} 5M~+F"Hl
,?Ie!r$6
l5=ih9u
Utility.log("Thread " + nThreadID + " is over!"); wkPjMmW+!
bDownOver = true; CbW[_\
//nPos = fileAccessI.write (b,0,nRead); [&4+ <Nl'
} '_V9FWDZ
catch(Exception e){e.printStackTrace ();} lyFlJmi,r
} ~OsLbz:
} N$#~&
PYWFz
2HSFMgy
//打印回应的头信息 i$p2am8f
public void logResponseHead(HttpURLConnection con) j1qU 4#Y
{ oJ*,a
for(int i=1;;i++) `L 1+j
{ N8df1>mW
String header=con.getHeaderFieldKey(i); aNY-F)XWa
if(header!=null) <`"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z/h]Jos
Utility.log(header+" : "+con.getHeaderField(header)); GDC@s<[k
else @[?ZwzY:9
break; iZiT/#,H2
} EI*~VFx
} P qC#[0Qy
+jZa A/
;,6C&|n]w
public void splitterStop() -0<vmU
{ [;7zg@Sa
bStop = true; 4i{Xs5zk
} <9 ^7r J
G1w$lc
AaxQBTB
} ubfh4
Vt3*~Beb
?wlRHVZ
/* yQ[;.<%v
**FileAccess.java 9XtO#!+48
*//文件访问(定位，写) -`{W~yz
package NetFox; h!JyFc
import java.io.*; %AtT(G(n
6;:D!},'c
<XG]aYBR
public class FileAccessI implements Serializable{ 9 Xl#$d5
6{^\7`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +D4m@O
RandomAccessFile oSavedFile; w' J`$=
long nPos; &n_f.oUc
Q|{b8K
;92xSe"Ww
public FileAccessI() throws IOException fap]`P~#L
{ IAGY-+8e
this("",0); mF~]P8
} ]NBx5m+y@i
u6?9#L(
*S.FM.r
public FileAccessI(String sName,long nPos) throws IOException 8@LWg d
{ x:~XZX\mwH
oSavedFile = new RandomAccessFile(sName,"rw"); "ldd&><
this.nPos = nPos; 4v_Hh<%
oSavedFile.seek(nPos); ,aUbB8
} 0fBwy/:
SPdEO3
=v::N\&
public synchronized int write(byte[] b,int nStart,int nLen) :x[()J~N
{ Ri`6X_xU
int n = -1; R= mTJ'y
try{ ^o _J0 ]m
oSavedFile.write(b,nStart,nLen); ^78N25RU(
n = nLen; aACPyfGQ
} a?nK|Q=e
catch(IOException e) YJHb\Cf.
{ `Rfe*oAf
e.printStackTrace (); 5NN;Fw+
} (!5Pl`:j"
MG.c`t/w
l#T%N@X
return n; psmDGSm,&
} Or?c21un
)V>OND
|hi,]D^Kc
} fVY I
j2IK\~W?-
BI-'&kPk
/* o[ks-C>jw
**SiteInfoBean.java k*6"!J%A
*/ 2*O#m
package NetFox; ^?(#%~NS
}za pN v
Y7g%nz[[
public class SiteInfoBean { ,4'y(X<R
Zqe$S +u
f1'X<VA
private String sSiteURL; //Site's URL C@:X9NU
private String sFilePath; //Saved File's Path FGP^rTP)e
private String sFileName; //Saved File's Name /0gr?I1wr7
private int nSplitter; //Count of Splited Downloading File 2bw), W
xSM1b5=Pu
nj;3U^
public SiteInfoBean() 'a JE+
{//nSplitter的缺省值为5 c;"e&tW
//default value of nSplitter is 5 KFO K%vbM
this("","","",5); nt()UC`5
} $MQ<QP
/{[<J<(8
yF6AI@y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W/t,7lPFb
{ c u";rnj
sSiteURL= sURL; 2 yANf
sFilePath = sPath; :/5GHfyj
sFileName = sName; #&r}J
this.nSplitter = nSpiltter; CP2wg .
r_Ou\|jU
4OJD_
} J!~kqNI
`^^t#sT
2(~Zl\
public String getSSiteURL() ..nVViZ
{ wy:Gy9\
return sSiteURL; '-N5F
} H?Sv6W.~
<>f;g"qS
O>nMeU
public void setSSiteURL(String value) *BM#fe
{ ackeq#
sSiteURL = value; P`Now7! GW
} D4hT Hh
U*yOe*>
QP50.P5g
public String getSFilePath() dwUDhQt3Q
{ +UX~'t_'v
return sFilePath; <+ [N*
} =$y J66e
J;wBS w%1
Q=DMfJ"
public void setSFilePath(String value) l"`VvW[
{ _e>N3fT
sFilePath = value; @VIY=qh
} wY%t# [T3
t@MUNW`Q
^;s/4
public String getSFileName() C%E~9_w
{ J| wk})?
return sFileName; FF^h(Ea
} 1Vz^?t:
"PN4{"`V
VKYljY0#
public void setSFileName(String value) b|Ge#o
{ C_q2bI
sFileName = value; Y-1K'VhT
} FMF mn|
lo6upirZX
I;wxgWOP
public int getNSplitter() k}nGgd6XD
{ x_<#28H!
return nSplitter; `~VL&o1>
} v9 /37AU
.L%pWRxA[
V?.=_T<
public void setNSplitter(int nCount) 3!sZA?q
{ $iy!:Did
nSplitter = nCount; y1}2hT0,
} +IbV
} _s0)Dl6K
( [a$Z2m
Aep](je
/* OMo/a%`
**Utility.java |k]]dP|:'
*/ WwWOic2
package NetFox; os;94yd)
r|uR!=*|?
N>a~k}pPH
public class Utility { ^q& Rl\
7CF>cpw
^pew'pHQ
public Utility() Ce}m$k
{ pnx^a}|px
adri02C/
H<ovIMd
} IaRwPDj6
F|!=]A<
//线程睡眠 9mXmghoCO
public static void sleep(int nSecond) Uj 4HVd
{ 1uKIO{d@
try{ ,+h<qBsV@
Thread.sleep(nSecond); >jTiYJI_M
} rc>}3?o
catch(Exception e) Tyaqa0
{ @m%B>X28F
e.printStackTrace (); !UPB4I
} WnOYU9;%
} >b0Bvx-
/>:$"+gKo
//日志 n.NWS/v_{
public static void log(String sMsg) r7}KV| M
{ GJE+sqMX1
System.err.println(sMsg); e8:O2!HW
} @44*<!da
(yuOY/~k/
|cuKC \
public static void log(int sMsg) 0d:t=LKw)
{ :wRfk*Ly
System.err.println(sMsg); sD?Ynpt
} %cDTq&Q
} Si23w'T
9)=bBQyr:
:TKx>~`
/* XrMw$_0)
**TestMethod.java K+L9cv4 |*
*/ +G!# /u1
package NetFox; !J{[XT
vg X7B4
z$g__q-
public class TestMethod { G i(
Cl&)#
4/3w *
public TestMethod() \f Kn} ]kG
{ ///xx/weblogic60b2_win.exe ei1;@k/
try{ b"td]H3h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M1 o@v0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &IDT[J
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9|@5eN:N
fileFetch.start(); /&@q*L
} y9@j-m&
catch(Exception e){e.printStackTrace ();} wNFx1u^/)
>XuPg(Ow
}9z$72;Qdq
} u9c^YCBM
t(.vX
2t?>0)*m
public static void main(String[] args) wXdt\@Qr
{ D]'8BS3
new TestMethod(); vt(}8C+
} XS&;8 PO
} 9MQwc
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