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)); v+G}n\F
} a[Txd=b
for(int i=0;i<nEndPos.length-1;i++) dA\>z[n=
{ }[ux4cd8Y
nEndPos = nStartPos[i+1]; ot(|t4^
} LUS7-~:F
nEndPos[nEndPos.length-1] = nFileLength; rw_&t>Ri;
} '>'h7F=tY
} PX2Ejrwj
Z''Fz(qMC
!i}G>*XH,
//启动子线程 t6-c{ZX>A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q2gc.]K\
for(int i=0;i<nStartPos.length;i++) !!Mp;h'}-
{ #8nF8J<4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pMa 3R3a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), glk I9~
nStartPos,nEndPos,i); Zb);08X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S)JZb_
fileSplitterFetch.start(); jcx/ZR
} >`,v?<>+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [.dNX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,,BNUj/:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lh?mN3-*
nEndPos = " + nFileLength); 0FTiTrTn
// fileSplitterFetch[nPos.length-1].start(); y~ ^>my7G
VFA1p)n
s/Q}fW$ex
//等待子线程结束 >2$Ehw:K^
//int count = 0; [HQ17
//是否结束while循环 9n8;eE08
boolean breakWhile = false; P]dDTh~e~
4Z]^v4vb
ua7I K~8l
while(!bStop) ~}4H=[Zu
{ S$muV9z2=
write_nPos(); mpr["C"l
Utility.sleep(500); :GL|:
breakWhile = true; 36Wuc@<H
F)DL/';
H@aCo(#
for(int i=0;i<nStartPos.length;i++) UxzwgVT
{ ]e?*7T]
if(!fileSplitterFetch.bDownOver) r OB\u|Pg
{ nV']^3b
breakWhile = false; IFpmf0;^
break; 9h*$P:S;1v
} z:<(b
} ?]h+En5z8
if(breakWhile) E8NIH!dI
break; G*J(4~Yw}
{p6",d."N&
|S>nfL{TQe
//count++; 3t%uUkXl
//if(count>4) S@_@hFV jd
// siteStop(); #+ n &
} Y>%A*|U%
X4%*&L
O8dDoP\F2
System.err.println("文件下载结束！"); I X\&lV
} ?>lmLz!e
catch(Exception e){e.printStackTrace ();} f<kL}B+,Og
} <;U"D.'
cJE2z2uW0
`5GJ,*{z
//获得文件长度 YT&_{nL#\
public long getFileSize() $V5Ol6@2
{ ap;UxWqx
int nFileLength = -1; mT-5Ok&TUe
try{ 8^< -;
URL url = new URL(siteInfoBean.getSSiteURL()); uc7Y8iO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6;(Slkv
httpConnection.setRequestProperty("User-Agent","NetFox"); B8a!"AQ~5
2M1yw "
R 8Iac[N
int responseCode=httpConnection.getResponseCode(); Y|B/(
if(responseCode>=400) o_\b{<^I
{ |h6@hB\
processErrorCode(responseCode); Zjo9c{\
return -2; //-2 represent access is error Jw {:1
} >u4uV8S
`L9o!OsQ
2ix_,yTO
String sHeader; Pv0OoN*eJ{
|c >
k5}i^^.
for(int i=1;;i++) dc lJ
{ Bwll [=_I
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vZ|-VvG
//Utility.log(in.readLine()); I;mtyS
sHeader=httpConnection.getHeaderFieldKey(i); SAo"+%
if(sHeader!=null) Y{p *$
{ [;I.aT}R!;
if(sHeader.equals("Content-Length")) ~r=TVHjqi
{ 8q tNK>D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "Ny_RF
break; *=;=VUu5
} OpH9sBnA
} Pv/P<i^
else AKAAb~{
break; 0/] @#G2
} AHZ6
} pl"|NZz 7;
catch(IOException e){e.printStackTrace ();} W/?D}#e<4
catch(Exception e){e.printStackTrace ();} K5w22L^=+
%LVk%kz
H56e#:[$
Utility.log(nFileLength); Ir}&|"~H
_n{N3da
j83p[qR7o
return nFileLength; '`3-X];p
} Ogjjjy84vM
S2fw"1h*x
)Ba^Igb}
//保存下载信息（文件指针位置） I[e7Up
private void write_nPos() MGmtA(
{ K7_)!=DcX
try{ _Yh4[TT~/
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5h20\b?=$
output.writeInt(nStartPos.length); /n"A%6S
for(int i=0;i<nStartPos.length;i++) .vT'hu
{ ?94da4p
// output.writeLong(nPos); h+$_:](PC
output.writeLong(fileSplitterFetch.nStartPos); #lct"8
output.writeLong(fileSplitterFetch.nEndPos); y*7ht{B
} ".w*_1G7U
output.close(); ; 9'*w=V
} UT^t7MY#O
catch(IOException e){e.printStackTrace ();} 3'.OghI
catch(Exception e){e.printStackTrace ();} hw1ZTD:Y
} jN*A"m
(U7%Z<
h_A}i2/{
//读取保存的下载信息（文件指针位置） LRbevpZ,
private void read_nPos() WO}JIExy
{ Cch1"j<k$
try{ O-&n5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pP".?|n
int nCount = input.readInt(); `*N0 Lbl]
nStartPos = new long[nCount]; m,.d< **
nEndPos = new long[nCount]; '2.F-~
for(int i=0;i<nStartPos.length;i++) @Qx;J<{+g
{ %b!p{p
nStartPos = input.readLong(); F_I! +
nEndPos = input.readLong(); ?29 KvT;#]
} (p2\H>pTr
input.close(); awC&xVf
} ucA6s:!={
catch(IOException e){e.printStackTrace ();} 1C|j<w=i
catch(Exception e){e.printStackTrace ();} iSsy_ |
} 3cfkJ|fuwe
h.7 1O"N
MA1,;pv6
private void processErrorCode(int nErrorCode) 8a05`ZdP
{ \<PX'mnO
System.err.println("Error Code : " + nErrorCode); @D60
} :))AZ7_
3PJ
1DLQZq
//停止文件下载 H$[--_dI{
public void siteStop() WrD20Q$9Q
{ :V_$?S
bStop = true; goHr#@
for(int i=0;i<nStartPos.length;i++) T+~~w'v0
fileSplitterFetch.splitterStop(); 0[hl&7 Ab@
S`*al<m
1-qQp.Wj
} mS);bs
} hyTi':
//负责部分文件的抓取 p jrA:;
**FileSplitterFetch.java G A7
*/ VvltVYOZA
package NetFox; B\("08x
dj]sr!q+
aG"UV\
import java.io.*; m|-O/6~
import java.net.*; (JM4W "7'
6dinC <[}
Z,d/FC#y(
public class FileSplitterFetch extends Thread { @*c+`5)_
Lv_6Mf(
8XY4
String sURL; //File URL !IGVN:E
long nStartPos; //File Snippet Start Position (Bmjz*%M
long nEndPos; //File Snippet End Position {`3;Pd`
int nThreadID; //Thread's ID De^is^{
boolean bDownOver = false; //Downing is over @lj
boolean bStop = false; //Stop identical Cw+ (,1
FileAccessI fileAccessI = null; //File Access interface 4bJ3uIP#
$h$+EE!
(te\!$
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nrf%/L
{ =LT({8
this.sURL = sURL; xw=B4u'z
this.nStartPos = nStart; A2+t`[w
this.nEndPos = nEnd; d?S<h`{x
nThreadID = id; jV7q)\uu^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r[?rwc^
} +0=RC^
*PMql$
++kiCoC
public void run() ,)QmQ^/
{ D'2O#Rj4q
while(nStartPos < nEndPos && !bStop) &FK=w]P
{ HML6<U-eS
=W4cWG?+
d[S!e`,iD
try{ ^X_%e|
URL url = new URL(sURL); W&*{j;e9%I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t4JGd)r
httpConnection.setRequestProperty("User-Agent","NetFox"); pa\]@;P1
String sProperty = "bytes="+nStartPos+"-"; '@:;oe@]
httpConnection.setRequestProperty("RANGE",sProperty); Nh+$'6yT%
Utility.log(sProperty); IBuuZ.=j2h
.*zQ\P
AG9U2x
InputStream input = httpConnection.getInputStream(); BShZ)t
//logResponseHead(httpConnection); Al` ;SWN
G's/Q-'[\
D~%cf
byte[] b = new byte[1024]; `QkzWy~V3
int nRead; JRo{z{!O6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V,Gt5lL&/!
{ pH*L8tT
nStartPos += fileAccessI.write(b,0,nRead); O{dx+f
//if(nThreadID == 1) 2N]y)S_<V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U}5uy9A
} JZc5U}i
;0BCM(>Wo
#A))#sT'R
Utility.log("Thread " + nThreadID + " is over!"); mj,r@@k:=+
bDownOver = true; OIoAqt
//nPos = fileAccessI.write (b,0,nRead); /qp`xJ
} $rlIJwqn
catch(Exception e){e.printStackTrace ();} X;0EgIqh3
} Tru`1/ 7I
} ML'R[~|
6-JnT_
iFHVr'Og'
//打印回应的头信息 $:xUXEi{
public void logResponseHead(HttpURLConnection con) e@q[Dv'mu
{ Dho~6K}"
for(int i=1;;i++) &/zsIx+
{ L3W ^ip4
String header=con.getHeaderFieldKey(i); AI)9E=D%
if(header!=null) dE^'URBiA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); epwXv|aSZ
Utility.log(header+" : "+con.getHeaderField(header)); b"zq3$6*
else w?/,LV
break; r>G$u
} %_z]iz4
} fkI<RgM
Zkz:h7GUG-
KE^_09
public void splitterStop() I|PiZ1]2Y
{ bWyXDsr+
bStop = true; :*8@MjZ4
} {66vdAu&h<
~k J#IA
jt]+(sx
} Te.hXCFD
SZ0Zi\W
5I<?HsK@
/* F>}).qx
**FileAccess.java O+e8}Tmm
*//文件访问(定位，写) \ 0CGS
package NetFox; `\qU.m0(j
import java.io.*; ypsCyDQK`
2T|L##C
%] Bb;0G
public class FileAccessI implements Serializable{ i|=XW6J%
cvC;QRx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Npu;f>g0_
RandomAccessFile oSavedFile; &zm5s*yNt
long nPos; %TR->F
8"4`W~ 3
H(g&+Wcu=
public FileAccessI() throws IOException T"0a&.TLj
{ 9!R!H&
this("",0); f{+8]VA
} "W1q}4_
=DqGm]tA
t,H,*2
public FileAccessI(String sName,long nPos) throws IOException )8vcg{b{d
{ s_kI\w4(x1
oSavedFile = new RandomAccessFile(sName,"rw"); M'g4alS
this.nPos = nPos; 6znm?s@~
oSavedFile.seek(nPos); bc 0|tJc
} P@Qo2zTh%
F-ZD6l9O
.f6_[cS;g
public synchronized int write(byte[] b,int nStart,int nLen) SGbo|Xe7:
{ 3Fr}8Dy
int n = -1; PffwNj/l
try{ K'71uW>
oSavedFile.write(b,nStart,nLen); L@+j8[3BX
n = nLen; sC}/?^q
} -OziUM1qs
catch(IOException e) fZGKVxo"
{ ZHB'^#b
e.printStackTrace (); ilNm\fQ.
} }%:?s6Ler
Y>z(F\
nbYaYL?&
return n; {b+IDq`)=
} g_}@/5?y
G3e%~
^ZV xBQKg
} ;Lu}>.t
9\"~G)
6HEl1FK{@
/* 6Qo6T][
**SiteInfoBean.java ~ PPGU1
*/ '}}DPoV
package NetFox; l@GpVdrv
@emZwN"m
uD5i5,q1Hs
public class SiteInfoBean { ,<[os
#VrT)po+
%ZxKN;
private String sSiteURL; //Site's URL pjoI};
private String sFilePath; //Saved File's Path 1k hwwoo
private String sFileName; //Saved File's Name _\1(7?0D
private int nSplitter; //Count of Splited Downloading File +6>Pp[%
1E-$f
`SU;TN0
public SiteInfoBean() 2L\h+)
{//nSplitter的缺省值为5 {vU '>pp
//default value of nSplitter is 5 "5e]-u'
this("","","",5); YvU#)M_h
} Oq.) 8E.
Mu:H'$"'H
C=Zuy^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Nd0Wt4=
{ weDv[b5i
sSiteURL= sURL; \Z~m6;
sFilePath = sPath; 5<S1,u5
sFileName = sName; 6jnRC*!?
this.nSplitter = nSpiltter; -~xd-9v?
G9gvOEI/
\2LCpN
} 1DBzD%@Oz
!K@yB)9
I4)vJ0
public String getSSiteURL() Obd!
{ `W/6xm(X5;
return sSiteURL; "C.$qk]
} _%>.t
R@EFG%|`_
Vt&I[osC
public void setSSiteURL(String value) O8lOr(|l
{ SrKF\h%/+
sSiteURL = value; QoW3*1o
} H1@"Yg8
jXdn4m/O
E8503
public String getSFilePath() aCTVY1
{ cbIW>IbM
return sFilePath; E>[~"~x"pV
} ~C[,P\,
_,'UP>Si
m1cyCD
public void setSFilePath(String value) nQgn^z#
{ D +oo5
sFilePath = value; EuAa
} 6$zUFIk
<&NR3^Eq
XYn$yR\dj
public String getSFileName() qlzL<
{ K[9<a>D`
return sFileName; {<i!Pm
} }Jc^p
CUtk4;^y#
II2oV}7?
public void setSFileName(String value) ;S%wPXj&
{ :r6 bw
sFileName = value; 6ZM<M7(V
} @3G3l|~>
q}8R>`Z{
W}e5 4-lu
public int getNSplitter() `j2z=5
{ ,p2 Di
return nSplitter; duM>(y
} M\GS&K$lq
$pD^O!I)?
FYi<+]HZ
public void setNSplitter(int nCount) q80?C.,`
{ Di L@NU!$q
nSplitter = nCount; @tP,l$O&
} n b{8zo
} w?R6$n`
lyT~>.?{
2{%BQq>C
/* 3sL#_@+yz
**Utility.java ~vt8|OOo0
*/ h?SUDk:2^
package NetFox; [m4<j
':fVb3A[*d
4f>Vg$4
public class Utility { qzH97<M}T
@Wv*`
"kL5HD]TC
public Utility() +Gjy%JFp
{ &2g1Oy~
D]0#A|nF
5-sxTp
} \;sUJr"$
S5XFYQ
//线程睡眠 * 5j iC
public static void sleep(int nSecond) [[)HPHSQ
{ 2qEy"DKu
try{ mbd@4u
Thread.sleep(nSecond); "B\qp"N
} l^SKd
catch(Exception e) v<c8qg
{ } o=g)
e.printStackTrace (); @hCGV'4
} 68D.Li
} uXp0D$a
LX3 5Lt
//日志 S2Wxf>bt2
public static void log(String sMsg) 7N:,F9V<
{ #-{4 Jx
System.err.println(sMsg); h qxe
} m=#2u4H4
u=4tW:W,
9SU;c l
public static void log(int sMsg) '91Ak,cWB
{ !]"T`^5,Y
System.err.println(sMsg); cLXMq"?C
} eQNYfWR
} | 0&~fY
Xl}>mbB
rSa3u*xB
/* \ET7
**TestMethod.java _|#)tWy}
*/ Bt.WRRpAB
package NetFox; Z*oGVr g
tewC *%3V
\Q &Kd|
public class TestMethod { 2AdV=n6Z
,H|V\\
Iz ,C!c
public TestMethod() P>)qN,a
{ ///xx/weblogic60b2_win.exe p{88v3b6
try{ khyVuWN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y0z}[hZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jPFA\$To
SiteFileFetch fileFetch = new SiteFileFetch(bean); U/TF,JUI
fileFetch.start(); UGAP$_j ]P
} d#A.A<p*
catch(Exception e){e.printStackTrace ();} C`DTPoXN
O8M;q!)y
9]|cs
} @Gl=1
<Nkj)`%5iK
T[c;},
public static void main(String[] args) zEa3a
{ p-;*K(#X
new TestMethod(); "zYlddh
} \[Q,>{^
} WJl&Vyl2FL
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