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)); W;_nK4$%'
} [OHxonU
for(int i=0;i<nEndPos.length-1;i++) |\QgX%
{ T~QWRBO
nEndPos = nStartPos[i+1]; 9!T[Z/}T
} P6!jRC"52'
nEndPos[nEndPos.length-1] = nFileLength; X'%E\/~u
} &L#UGp$,
} .zS?9MP
8*8Zc/{
ki[UV zd
//启动子线程 Fkvl%n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g$HwxA9Gp/
for(int i=0;i<nStartPos.length;i++) .}'qUPNR
{ xB_!>SqF1U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }MRd@ 0-?!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MHSs!^/g5
nStartPos,nEndPos,i); tYZ[68
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Mo=PWI1?
fileSplitterFetch.start(); Xg<*@4RD8
} SeHagKA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :80Z6F.k`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZaeqOVp/j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *_R]*o!W'
nEndPos = " + nFileLength); KiI!frm1
// fileSplitterFetch[nPos.length-1].start(); O?U'!o=
)_{dWf1
ulu9'ch
//等待子线程结束 /E Bo3`
//int count = 0; XD|E=s
//是否结束while循环 x;-. ZVF
boolean breakWhile = false; C3< m7h
8i6Ps$T
v[#9+6P=
while(!bStop) 9UKp?SIF
{ hc~s"Atck
write_nPos(); D!.[q-<
Utility.sleep(500); ()K " c#
breakWhile = true; " Om[~-31
Of{/t1o?
KC(xb5x Y
for(int i=0;i<nStartPos.length;i++) Atflf2K
{ $rz=6h
if(!fileSplitterFetch.bDownOver) $Z|ffc1
{ fQ/ 0R
breakWhile = false; hQ]H /+\
break; =0^Ruh
} HFwN
} BDVHol*g
if(breakWhile) ]?3un!o3o
break; zXv3:uRp.
&C_'p{G
AFc$%\s4
//count++; 0TN;86Mo
//if(count>4) =Vy`J)z9
// siteStop(); &8%e\W\K:/
} <,3^|$c%
%6L^2 X
b8LoIY*
System.err.println("文件下载结束！"); @?=|Y
} 1U^A56CN
catch(Exception e){e.printStackTrace ();} /rq VB|M
} S|apw7C
|~'IM3Jw(Y
M@4UGM`J
//获得文件长度 >tO`r.5u9
public long getFileSize() nA P.^_K
{ L,mQ
int nFileLength = -1; PH?#)lD
try{ `D`sr[3n
URL url = new URL(siteInfoBean.getSSiteURL()); [[>wB[w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I4i2+ *l}
httpConnection.setRequestProperty("User-Agent","NetFox"); *g y{]
j7sKsbb
0G7K8`a
int responseCode=httpConnection.getResponseCode(); u}!@ ,/)
if(responseCode>=400) 'd+NVj{C
{ MS0Fl|YA
processErrorCode(responseCode); dFH$l
return -2; //-2 represent access is error Fx5d:!]:$?
} kGdt1N[
66.5QD0
JNkwEZhHyg
String sHeader; vhsk0$f
A81ls#is
U+)xu>I
for(int i=1;;i++) 3dht!7/
{ w"OP8KA:^T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L3G \
//Utility.log(in.readLine()); F%i^XA]a*
sHeader=httpConnection.getHeaderFieldKey(i); |tv"B@`
if(sHeader!=null) mN!lo;m5
{ =+-Yxh|*
if(sHeader.equals("Content-Length")) jeGj<m
{ 0A,]$Fzt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F)s{PCl
break; w3=%*<
} dxZu2&gi
} Ix(?fO#uNF
else UJfEC0
break; YqPQ%
} uq, {tV
} x~GQV^(l3
catch(IOException e){e.printStackTrace ();} UB 6mqjPK
catch(Exception e){e.printStackTrace ();} K'X2dG*
A5i:x$ww
P(XaTU&-
Utility.log(nFileLength); s3]?8hXd
9G{;?c
*xON W
return nFileLength; Pu"R,a
} K4]g[z
hoQs @[
)//I'V
//保存下载信息（文件指针位置） AC;V m: @{
private void write_nPos() u0#}9UKQ
{ VQ0fS!5'
try{ q EP 4
output = new DataOutputStream(new FileOutputStream(tmpFile)); hSFn8mpXT
output.writeInt(nStartPos.length); ax{ ;:fW
for(int i=0;i<nStartPos.length;i++) _~rI+lA
{ RRGWC$>?
// output.writeLong(nPos); ]J:1P`k.
output.writeLong(fileSplitterFetch.nStartPos); W?eu!wL#p
output.writeLong(fileSplitterFetch.nEndPos); }~"hC3w
} x_c7R;C
output.close(); ZTU&,1Y;
} rAs,X
catch(IOException e){e.printStackTrace ();} 2Fz|fW_
catch(Exception e){e.printStackTrace ();} VxY+h`4#
} 7zHh@ B:]
m;D- u>o
Wm);C~Le
//读取保存的下载信息（文件指针位置） $KLD2BAL
private void read_nPos() mwY IJy[
{ J?Dq>%+^
try{ txcf=)@>V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g8w2Vz2/
int nCount = input.readInt(); )ZBY* lk9
nStartPos = new long[nCount]; _UT$,0u_i
nEndPos = new long[nCount]; ^2$ lJ
for(int i=0;i<nStartPos.length;i++) qNm$Fx
{ -jn WZ5.
nStartPos = input.readLong(); x5QaM.+=J
nEndPos = input.readLong(); ^S)cjH`P
} Pt&(npjN,
input.close(); 'yV?*a
} b8%C*r7
catch(IOException e){e.printStackTrace ();} WBNw~|DO]
catch(Exception e){e.printStackTrace ();} ^-rfvc
} qwK2WE%T
\EKU*5\Hp>
CBDG./
private void processErrorCode(int nErrorCode) {5d9$v7k4
{ rQEyD
System.err.println("Error Code : " + nErrorCode); 5w\fSY
} 52b*[tZ
K{ \;2M
`E!N9qI?t$
//停止文件下载 <)\y#N
public void siteStop() 7lS#f1E
{ p/2jh&
bStop = true; {@<J_A
for(int i=0;i<nStartPos.length;i++) &f7fK|}
fileSplitterFetch.splitterStop(); V\})3i8
"dROb}szn
bu=?N
} @^;j)%F}
} N?5x9duK
//负责部分文件的抓取 w|CZ7|6
**FileSplitterFetch.java sTOa
*/ Qb!PRCHQ
package NetFox; Z0`T\ay
;L|uIg;.s
+uBLk0/)>
import java.io.*; 2_ :n
import java.net.*; f>s?4
r}0\}~'?c
?H_LX;r
public class FileSplitterFetch extends Thread { [! 'op0
2P]L9'N{Y
CH fVQ|!\
String sURL; //File URL :>aQ~1f>]
long nStartPos; //File Snippet Start Position `xz<>g9e
long nEndPos; //File Snippet End Position / }Rz=&
int nThreadID; //Thread's ID }lK3-2Pk
boolean bDownOver = false; //Downing is over T]j.=|,d
boolean bStop = false; //Stop identical Wd0[%`dq
FileAccessI fileAccessI = null; //File Access interface Yp0/Ab(v
4GR!y)
{8R"O{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ATy*^sc&"
{ <BSc* 9Q
this.sURL = sURL; P_c,BlfGMH
this.nStartPos = nStart; uZZU{U9h
this.nEndPos = nEnd; 7},)]da>,'
nThreadID = id; w=|GJ0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .TE?KI
} R/^u/~<
`+t.!tv!
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public void run() Y=`
{ h?-#9<A
while(nStartPos < nEndPos && !bStop) (;%|-{7e-
{ GZ{]0$9I'
,+g&o^T
bsd99-_(4
try{ -!0_:m3
URL url = new URL(sURL); yQ3OL#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &QG6!`fK}3
httpConnection.setRequestProperty("User-Agent","NetFox"); VdP`a(Yd;
String sProperty = "bytes="+nStartPos+"-"; {QbvR*gv
httpConnection.setRequestProperty("RANGE",sProperty); y7S4d~&
Utility.log(sProperty); /m(=`aRt
lNv".Y=l
$7QoMV8V
InputStream input = httpConnection.getInputStream(); zE)~0v4
//logResponseHead(httpConnection); Fb/XC:AD
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Sa"9^_.2#
byte[] b = new byte[1024]; Dfd-^N!
int nRead; SlSM+F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EZ.!rh~+
{ R.LL#u};
nStartPos += fileAccessI.write(b,0,nRead); m%"uPv\
//if(nThreadID == 1) pq:7F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <xJ/y|{
} #q3l!3\mW
kz"3ZDR
Y%|@R3[Nk
Utility.log("Thread " + nThreadID + " is over!"); eUl/o1~mXa
bDownOver = true; l{VSb92f
//nPos = fileAccessI.write (b,0,nRead); |!q$_at
} @HBEt^!
catch(Exception e){e.printStackTrace ();} +3i7D
} 'a^{=+
} pG^}Xf2a
>K# ,cxY
=`Y.=RL+'n
//打印回应的头信息 Y~)T
public void logResponseHead(HttpURLConnection con) ^uS/r#l
{ OG3/-K8R
for(int i=1;;i++) b dJ+@r
{ E42eOGp9i
String header=con.getHeaderFieldKey(i); ]APvp.Tw:
if(header!=null) dr{y0`CCN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -[OXSaf6
Utility.log(header+" : "+con.getHeaderField(header)); Omi^>c4G
else ?EU\}N J
break; |wox1Wt|E
} 8h<ehNX ^I
} $6F)R|
xsjO)))f
pPVRsXy
public void splitterStop() s cdtWA
{ 1Uf*^WW4
bStop = true; +Z!;P Z6
} =2y8CgLj
\n9A^v`F/
#'OaKt?Z)
} xt4)Ya
fag^7rz
w62=06`@
/* Q,Z*8FH=
**FileAccess.java `(0LK%w
*//文件访问(定位，写) bXYA5wG
package NetFox; ==/n(LBD
import java.io.*; $jI>[%
TP1S[`nR
,}xbAA#
public class FileAccessI implements Serializable{ P6Bl *@G
6zIgQ4Bp24
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *m+5Pr`7
RandomAccessFile oSavedFile; u)Q;8$`
long nPos; )a=/8ofe
^D@b;EyK
ig0u^BC
public FileAccessI() throws IOException Q36)7=at
{ V 'X;jC
this("",0); :L0/V~D
} Lc<eRVNd,
%lr|xX
'f/Lv@]a
public FileAccessI(String sName,long nPos) throws IOException +VEU:1Gt
{ 5/m$)wE
oSavedFile = new RandomAccessFile(sName,"rw"); <-UOISyf
this.nPos = nPos; J NC
oSavedFile.seek(nPos); n,P5o_^:
} Swtbl`,
:9l51oE7
\g-j9|0
public synchronized int write(byte[] b,int nStart,int nLen) ,`td@Y
{ g"Qh]:
int n = -1; 5;)*T6Y
try{ %'L;FPxB
oSavedFile.write(b,nStart,nLen); |!d"*.Q@F
n = nLen; =A[5= k>
} tPHS98y
catch(IOException e) 1'6cGpZY
{ ZF#Rej?
e.printStackTrace (); o%M<-l"!/
} Bk|K%K
Nq8@Nyp
WVkR56
return n; iO!6}yJ*V
} tUE'K.-
(L6Cy%KgV
y[0`hSQ)~
} j<tq1?? [b
eukA[nO7G
!- ~X?s~L
/* 3+OsjZ
**SiteInfoBean.java kpfwqHT
*/ e[Xq
package NetFox; m.%`4L^`T
Aq#/2t
#y"=Cz=1u7
public class SiteInfoBean { ,*,sw:=2
$*~Iu%Az
g?/XZ5$a5
private String sSiteURL; //Site's URL US?Rr
private String sFilePath; //Saved File's Path ~el-*=<m
private String sFileName; //Saved File's Name _JGs}aQ
private int nSplitter; //Count of Splited Downloading File j kn^Z":
~krS#\
?~ULIO'
public SiteInfoBean() 9$d.P6|d>
{//nSplitter的缺省值为5 ~waNPjPRG
//default value of nSplitter is 5 M<8ML!N0;t
this("","","",5); )JgC$ <
} |qjZ38;6
#I\Y=XCY
Mpx/S<Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |ek ak{js
{ ?;7b*Z
sSiteURL= sURL; gb-{2p>}
sFilePath = sPath; PjqeE,5
sFileName = sName; @Gjny BJ
this.nSplitter = nSpiltter; X,fu!
A[/I#Im7
2P~)I)3V
} A! 6r/
)3E,D~1e%
cwtD@KC[B
public String getSSiteURL() g@nk.aRw
{ SX+RBVZU
return sSiteURL; #n})X,ip2
} 66ohmP@04Z
^7XAw: ?
}Zl"9A#K
public void setSSiteURL(String value) Px4/O~bLk
{ oNRG25
sSiteURL = value; NCt~9xS.
} Up?=m^
CB}BQd
sk X]8
public String getSFilePath() BnEdv8\,&s
{ rFd@mO
return sFilePath; x*8O*!ZZ
} f~\Xg7<
6M><(1fT
$-G`&oT
public void setSFilePath(String value) Lar r}o=
{ ^Vo"fI`=C
sFilePath = value; g6' !v
} W,NL*($^
E/O5e(h
E 5kF^P
public String getSFileName() PW[6/7
{ ju{%'D!d9
return sFileName; X8 qIia
} T_ ^C#>
R^{xwI
cC6z,0`3
public void setSFileName(String value) }:#dV B+
{ 0\ f-z6
sFileName = value; ~iTxv_\=6u
} 6Y?`=kAp
5H.Db
%x2b0L\g
public int getNSplitter() )/%S=c
{ 84`rbL!M
return nSplitter; xXOw:A'
} XS/n>C
V*qY"[
{8m1dEC^@Q
public void setNSplitter(int nCount) _Y#Bm/*
{ {%7<"
nSplitter = nCount; ~I$}#
} =R9*;6?N
} >h7$v~nra
T&/_e
nLd~2qBuv
/* &z ksRX
**Utility.java 5P\N"Yjx'
*/ _;G=G5r
package NetFox; iwo$\
~07RFR
NhDA7z`b'J
public class Utility { 4K,''7N3
BTs0o&}e
`vEqj v
public Utility() b`]M|C [5
{ 1f;or_f#k?
UPO^V:.R4
ysth{[<5F3
} 5&(3A|P2
\3j)>u,r
//线程睡眠 4WG=m}X
public static void sleep(int nSecond) #Q+R%p[D
{ H5p5S\g-)
try{ \\s?B K
Thread.sleep(nSecond); =h[yAf
} @YB85p"]J.
catch(Exception e) R-C5*$
{ ,RN|d0dE
e.printStackTrace (); E0jUewG
} A^vvST%7
} u*k*yWdr
3{q[q#"
//日志 `oPLl0
public static void log(String sMsg) aH^{Vv$]M@
{ [a+4gy
System.err.println(sMsg); ^Fvr f`A'
} T^NJ4L4#
o'^phlX
Z"N(=B
public static void log(int sMsg) kxy]vH6m
{ qOgtGN}k
System.err.println(sMsg); bQV("~#
} 2$)mC9
} <4$YO-:E
X#7}c5^Y
PvuAg(?
/* D+hB[*7Fs
**TestMethod.java 19w_tSg
*/ c.-cpFk^L&
package NetFox; ;%!tf{Si
$2is3;h
wO!% q[
public class TestMethod { >F|qb*Tm7
d/4ubf+$k
Ff&R0v
public TestMethod() F7V6-V{_
{ ///xx/weblogic60b2_win.exe 8.-S$^hj~6
try{ nHVPMi>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h,.fM}=H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OsB?1;:
SiteFileFetch fileFetch = new SiteFileFetch(bean); soxfk+ 9
fileFetch.start(); 6~3jn+K$1
} H.9yT\f.
catch(Exception e){e.printStackTrace ();} }M?|,N6
{YBl:rMz
'DeW<Sa~
} a>?p.!BM
LhZZc`|7t
YPG,9iZ&f
public static void main(String[] args) <oZ(ng@X
{ A$N+9n\
new TestMethod(); oL)lyUVT
} =kF?_KN
} lh~<s2[R2
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