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)); 5uahfJk
} US3)+6
for(int i=0;i<nEndPos.length-1;i++) .-![ ra
{ S.B?l_d^
nEndPos = nStartPos[i+1]; Y\WVkd(+G
} @ S[As~9X
nEndPos[nEndPos.length-1] = nFileLength; VpAwvMw
} K(lSR
} O(2c_!d
)=X g
*PV7s
//启动子线程 !iNwJ|0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'J-a2oiM(
for(int i=0;i<nStartPos.length;i++) MzgP@tB
{ q5hE S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o _l_Yi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MUv#8{+F'/
nStartPos,nEndPos,i); V*fv>f:Yv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dlCiqY:}
fileSplitterFetch.start(); 9W]OtSG
} _?cum~A@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L@=$0p41;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lF.kAEC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6__!M
nEndPos = " + nFileLength); G~bDl:k`A
// fileSplitterFetch[nPos.length-1].start(); @RszPH1B
T?d}IDv1
(3D&GY!/
//等待子线程结束 /5"T46jD
//int count = 0; vY|YqWt
//是否结束while循环 "u^vBd[}
boolean breakWhile = false; ezY^T
_>;MQ)Km~
<)~-]
while(!bStop) IQtQf_"e1
{ ~8mz.ZdY
write_nPos(); 4lc|~Fj++
Utility.sleep(500); &g5PPQ18
breakWhile = true; 1:^Xd~X
5Rs#{9YE
+^esL9RG:
for(int i=0;i<nStartPos.length;i++) Me?I8:/
{ hLuv
if(!fileSplitterFetch.bDownOver) 3<M yb
{ X])iQyN
breakWhile = false; Q4LPi;{\
break; (tVT&eO
} 0x5Ax=ut
} =. \hCgq
if(breakWhile) r"{jrBK$
break; %s+'"E"E
;ZAwf0~
ovM;6o
//count++; f sh9-iY8e
//if(count>4) V,Nu!$)J
// siteStop(); 6.KEe^[-
} Z#Nw[>NN*
c?_7e9}2
_z BfNz9D
System.err.println("文件下载结束！"); )~R[aXkvY
} K/N{F\
catch(Exception e){e.printStackTrace ();} W3>9GY90R
} pKq[F*Lut
L YB@L06a
M$@~|pQ<
//获得文件长度 Y ?n4#J<
public long getFileSize() 3fQ`}OcNr
{ G93V=Bk=
int nFileLength = -1; Zv9JkY=+@
try{ E8#aE\'t
URL url = new URL(siteInfoBean.getSSiteURL()); X,3\c:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =0EKrG
httpConnection.setRequestProperty("User-Agent","NetFox"); 2>k*9kyp
XK/l1E3N
80Fa i
int responseCode=httpConnection.getResponseCode(); yBs-bp"-
if(responseCode>=400) ]nRf%Vi8g
{ P,)D0i
processErrorCode(responseCode); }`QZV_
return -2; //-2 represent access is error W&9qgbO]
} +kYp!00
FqbGT(QB0
5&EBUl}
String sHeader; 6AY(/N8V
b,+KXx
svEe@Kt`
for(int i=1;;i++) YV|_y:-
{ fm^`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !=,zy
//Utility.log(in.readLine()); 0H4|}+e
sHeader=httpConnection.getHeaderFieldKey(i); kBC$dW-
if(sHeader!=null) gS[B;+d
{ ]5a3e+
if(sHeader.equals("Content-Length")) Wm"#"l4
{ nPI$<yW7F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F?a 63,r
break; *74/I>i
} Y{dX[^[
} 9@"pR;X@
else yLCMu | +
break; N\tFK*U^I
} PPG+~.7
} @.k^ 8hc
catch(IOException e){e.printStackTrace ();} H6nH
catch(Exception e){e.printStackTrace ();} ->;2CcpHB
f0^s<:*
a"O;DYh
Utility.log(nFileLength); b5%<},ySq
{y5 L
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return nFileLength; 9L-jlAo<
} St!0MdCH
|%XcI3@*
lq3D!+m
//保存下载信息（文件指针位置） e#}Fm;|d
private void write_nPos() ydY(*]
{ 1D[>oK\
try{ [h B$%i]\<
output = new DataOutputStream(new FileOutputStream(tmpFile)); U8>4ClJ4
output.writeInt(nStartPos.length); jFKp~`/#
for(int i=0;i<nStartPos.length;i++) "B+F6
{ PvW4%A@0
// output.writeLong(nPos); ->IZZ5G<
output.writeLong(fileSplitterFetch.nStartPos); ~bzac2Rp
output.writeLong(fileSplitterFetch.nEndPos); 4DL2 A;T
} b$nev[`{6
output.close(); wXnVQ-6H
} UB8n,+R
catch(IOException e){e.printStackTrace ();} I} Q+{/?/
catch(Exception e){e.printStackTrace ();} ui`EODhA(
} {=J:
w3b?i89
hRB?NM
//读取保存的下载信息（文件指针位置） Vz-q7*o$S
private void read_nPos() =\5f_g2M
{ ]^wr+9zd
try{ 3gJZlH5IR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;[P>
int nCount = input.readInt(); ?5};ONjN
nStartPos = new long[nCount]; Vep41\g^
nEndPos = new long[nCount]; };P=|t(r
for(int i=0;i<nStartPos.length;i++) H!"TS-s`
{ -nUK%a"(D
nStartPos = input.readLong(); #E\6:UnT
nEndPos = input.readLong(); z9 #-
} .ej+?QYwC
input.close(); <|G!Qn?2-
} GCw4sb4~w
catch(IOException e){e.printStackTrace ();} 7042?\\=
catch(Exception e){e.printStackTrace ();} h|Qb:zEP,
} ~d\V>
3'A0{(b
/$\8?<Pc".
private void processErrorCode(int nErrorCode) 8D?$@!-
{ :mLXB75gH
System.err.println("Error Code : " + nErrorCode); #CyqiOM\*
} ^liW*F"UY
&{qKoI]
TOa6sB!H
//停止文件下载 DC BN89#
public void siteStop() { JDD"z
{ mZ:#d;0
bStop = true; 8~RJnwF^
for(int i=0;i<nStartPos.length;i++) [Ne'2z
fileSplitterFetch.splitterStop(); 4 540Lw'A
G7-k ,P^
gyh8
} >YF=6zq.`
} 2cGiE{
//负责部分文件的抓取 ;g2UIb?{6
**FileSplitterFetch.java yFd942
*/ ,jw`9a
package NetFox; Z8Vof~
II~91IEk
j]R[;8g
import java.io.*; LH`2Y,E
import java.net.*; 4Xt`L"f
u.?jWvcv
WT1y7+_g(d
public class FileSplitterFetch extends Thread { kFyp;=d:K
#O8=M(- V
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String sURL; //File URL \M0's&1(
long nStartPos; //File Snippet Start Position ^\J-LU|"B
long nEndPos; //File Snippet End Position '(N(k@>{
int nThreadID; //Thread's ID Zp<#( OIu
boolean bDownOver = false; //Downing is over |68/FJZ,5
boolean bStop = false; //Stop identical +bJ~S:[
FileAccessI fileAccessI = null; //File Access interface E_Y!in 70
|m@>AbR5dk
O2="'w'kR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rwgj]
{ w8J8III\~
this.sURL = sURL; Ss\?SEq
this.nStartPos = nStart; HNj;_S
this.nEndPos = nEnd; 5tLb o
nThreadID = id; m!P<# |V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^}wF^ _
} /_Ku:?{
hk S:_e=
/<(-lbq,
public void run() ji.?bKqHE
{ , `EOJ"|
while(nStartPos < nEndPos && !bStop) Yw5-:w0f
{ +/]*ChrS
_p'@.P
&%qDi_UD
try{ |k%1mE(+=s
URL url = new URL(sURL); e+4Eiv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X')l04P@%
httpConnection.setRequestProperty("User-Agent","NetFox"); 4*5e0:O
String sProperty = "bytes="+nStartPos+"-"; VEn3b
httpConnection.setRequestProperty("RANGE",sProperty); ?d{O'&|:
Utility.log(sProperty); fk>{
DQc\[Gq&
ZU+_nWnl
InputStream input = httpConnection.getInputStream(); zDbO~.d
//logResponseHead(httpConnection); oayu*a.
U|\ .)h=
I;eoy,
byte[] b = new byte[1024]; y'>JT/Q5
int nRead; %.l={B,i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |JHNFs
{ *p#@W-:9E
nStartPos += fileAccessI.write(b,0,nRead); ^yq}>_
//if(nThreadID == 1) 4m"0R\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #d/T7c#
} <mVFC
8"-=+w.CZ
ED" fi$
Utility.log("Thread " + nThreadID + " is over!"); w%\{4T~
bDownOver = true; <p/2hHfiD
//nPos = fileAccessI.write (b,0,nRead); N mxh zjJ
} M6^ \LtFt
catch(Exception e){e.printStackTrace ();} K9p<PLy+
} +'MO$&6
} D_~;!^
xa<KF
z/f._Z(
//打印回应的头信息 [[6"qq
public void logResponseHead(HttpURLConnection con) (FaYagD
{ bM:4i1Z
for(int i=1;;i++) tgi%#8ZDpz
{ Iz. h
String header=con.getHeaderFieldKey(i); 1IS1P)4_0
if(header!=null) D M+MBK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]sL.+.P
Utility.log(header+" : "+con.getHeaderField(header)); t!6uz
else JehanF[
break; ]y=U"g
} +_cigxpTc
} 3HYdb|y
ecJjE 56P
<PuY"-`/Oc
public void splitterStop() U]vUa^nG
{ N0kCdJv
bStop = true; lnyq%T[^
} %7aJSuQN%
eF.nNu
:f39)g5>
} LmqSxHs0Q
<Z3C&BM
LTo!DUi`
/* Ao`e{
**FileAccess.java Oy=0Hsh@x
*//文件访问(定位，写) 2#lpIj
package NetFox; (_@5V_U
import java.io.*; gL&w:_
VV/T)qEe7>
lqL5V"2Y
public class FileAccessI implements Serializable{ @YH>|{S&
85Yi2+8f4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \:1$E[3v
RandomAccessFile oSavedFile; "i/GzD7`n
long nPos; c|9g=DjK
=CD6x= l6
!wpK +.D
public FileAccessI() throws IOException EHn!ZrQgh
{ jFe8s@7
this("",0); s-Yu(X2
} [u K,.G
8gEp5
NJr)f
public FileAccessI(String sName,long nPos) throws IOException SUMfebW5
{ e\[q3J
oSavedFile = new RandomAccessFile(sName,"rw"); YB4 ZI
this.nPos = nPos; gvo98Id
oSavedFile.seek(nPos); lg$aRqI29
} Hkia&nz'3
+,)k@OI
uuFQTx))
public synchronized int write(byte[] b,int nStart,int nLen) <>n|_6'$90
{ i7h^L)M
int n = -1; v}t{*P
try{ Zh;}Q(w
oSavedFile.write(b,nStart,nLen); FN!?o:|(
n = nLen; diM*jN#
} RbxQTM_:M
catch(IOException e) _^b\#Jz4U3
{ V*te8HIe
e.printStackTrace (); Jf7H;ZM<
} x2)WiO/As
5TuwXz1v
[T7&)p
return n; &4WA/'>R
} ^C^I
iY@}Q "
R#~l[S8u^
} dPpQCxf
DUu:et&c1
oupWzjo
/* ^u$=<66
**SiteInfoBean.java MNe/H\
*/ |-/@3gPO
package NetFox; JiXE{(
)_!a:
( EJ1g^|"
public class SiteInfoBean { _8 K|2$X
vYXhWqL~
s1Wn.OGR4
private String sSiteURL; //Site's URL AtHkz|sl
private String sFilePath; //Saved File's Path ;t9_*)[
private String sFileName; //Saved File's Name b}Im>n!
private int nSplitter; //Count of Splited Downloading File R1Rk00Ow:
(Lz|o!>
(HeSL),1
public SiteInfoBean() S\I+UeFkf
{//nSplitter的缺省值为5 b9?Vpu`?
//default value of nSplitter is 5 'Tqusr>lPY
this("","","",5); `]GL3cIh:
} V:5aq.o!
G2!<C-T{2
a|t{1]^w`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s-SFu
{ h|'|n/F
sSiteURL= sURL; >HwVP.~HN
sFilePath = sPath; (?,jnnub
sFileName = sName; _f>)G3p
this.nSplitter = nSpiltter; j8?! J^TC
~qL/P 5*+
gxI/MD~!>
} 8VG~n?y
_N|AI"sj.
w0sy@OF
public String getSSiteURL() JCZ&TK
{ o(v7&m;
return sSiteURL; rWO#h{
} y[cc<wm$
%t9Kc9u3p
Xooh00
public void setSSiteURL(String value) Ya<KMBi3
{ !](Mt?e
sSiteURL = value; Mjl,/-0 w
} $OGMw+$C^
6oq^n s-
Ym -U{a
public String getSFilePath() Pq-@waH3
{ b=WkRj
return sFilePath; :m'(8s8
} ~<Wa$~oY
0&&P+adk
v33[Rk'
public void setSFilePath(String value) ?"}U?m=
{ 8)`
sFilePath = value; \0qFOjVj
} @ K2Ncb7
j~;y~Cx?
EjEXev<]
public String getSFileName() bgInIe
{ b3GTsX\2|
return sFileName; NY[48H
} rX`fjS*C
5rA>2<\pQ
-/7@ A
public void setSFileName(String value) V*6&GM&
{ qX[C%
sFileName = value; ]@}@G[e#[
} N=8CVI
OXoEA a
O=1#KNS
public int getNSplitter() ^#7&R"
{ ^M1O)
return nSplitter; FQMA0"(G$
} :3}K$
_xP@kN~
<g8{LG0
public void setNSplitter(int nCount) MY&?*pV)
{ z`8>$9
nSplitter = nCount; # kmI#W"^
} B8V85R
} Nn5sD3z#
lWU? R
@Z~0!VY
/* /Dk`?
**Utility.java vRO`hGH
*/ bgmOX&`G
package NetFox; K5d>{c
072`i46
?kc,}/4
public class Utility { gHU0Pr9'
LoS%FI
}e,*'mCC*
public Utility() EPeV1$
{ p:|p?
a^9}ceu?
`q1K%id
} 9'\*Ip^
X]%n#\t,]
//线程睡眠 r6`KZ TU
public static void sleep(int nSecond) MqswYK-s
{ sMb+4{W&6
try{ ep\a
Thread.sleep(nSecond); uTUkRqtD!
} ?|we.{
catch(Exception e) Z<tJ+
{ |Ns[{/
e.printStackTrace (); ob>2SU[Y
} SNf*2~uq)
} [,p[%Dza
e@crM'R7Lo
//日志 L[7Aa"R
public static void log(String sMsg) OLxiY r
{ S4(lC%$|
System.err.println(sMsg); |<1
} ]W 6!Xw)[
pWXoJ0N
dJd(m&.|N
public static void log(int sMsg) *b]$lj
{ *4F6U
System.err.println(sMsg); a-7T
} ojZvgF
} (y!<^Q
'uw=)8t7
} ^67HtNQ
/* Mk@%Wuxg2
**TestMethod.java $&iw(BIq
*/ BliL1"".
package NetFox; n[pW^&7x
StJ&YYdD
vEIDf{
public class TestMethod { A~Ov(
8P=z"y
48 `k"Uy
public TestMethod() \vvV=iw
{ ///xx/weblogic60b2_win.exe &}G2;O}3
try{ [vs5e3B)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CPCjY|w7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w(KB=lA2
SiteFileFetch fileFetch = new SiteFileFetch(bean); jNa'l<dn]
fileFetch.start(); A\7qPfpG
} 8QN#PaY
catch(Exception e){e.printStackTrace ();} o%E^41M7E
pIy+3&\e;
pO.+hy
} >Hq)1o
2.zx
uIkB&
public static void main(String[] args) [80L|?, *
{ *uq;O*s
new TestMethod(); 11s*C #
} JC6Bs`=s~
} R7)2@;i
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