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)); .fbYB,0w
} l'W3=,G[?
for(int i=0;i<nEndPos.length-1;i++) /(y4V
{ _d/GdeLs
nEndPos = nStartPos[i+1]; rtcJ=`)0`
} 2V 4`s'
nEndPos[nEndPos.length-1] = nFileLength; *>G^!e.u
} *m iONc
} Pu1GCr(
>y&[BB7S6
bJANZn|H
//启动子线程 5 Xk~,%-C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #j\*Lc"Ur:
for(int i=0;i<nStartPos.length;i++) $#TID=
{ `CPZPp,l6`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s z;=mMr/Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), md.*
nStartPos,nEndPos,i); }R4(B2vup
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m2jwqx{G
fileSplitterFetch.start(); ~WzMK
} ~}epq6L>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3O#~dFnp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GU2]/\W*a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", owP6dtd)
nEndPos = " + nFileLength); o]dK^[/*
// fileSplitterFetch[nPos.length-1].start(); \o0z@Ntq
M4R%Gr,La
f S(^["*G
//等待子线程结束 6'S5sRA
//int count = 0; YCtIeq%
//是否结束while循环 `MN&(!&C*
boolean breakWhile = false; .%|OGl ?
{ +i;e]c
^H f+du
while(!bStop) @ARAX\F
{ "K9vm^xP
write_nPos(); !a.3OpQ
Utility.sleep(500); W ]a7&S
breakWhile = true; FRb&@(;
mMel,iK=
$_4oN(WSz
for(int i=0;i<nStartPos.length;i++) jI@bTS o
{ U/}AiCdj@
if(!fileSplitterFetch.bDownOver) Pc/.*kOT
{ cP/F|uG5
breakWhile = false; MBnK&GS
break; pE9aT5 L
} #p11D= @[
} u40b? n.
if(breakWhile) oVKsic?
break; ]9bh+
-U/I'RDLEz
$}^Rsv(
//count++; m0dFA<5-
//if(count>4) gt].rwo"
// siteStop(); }dV9%0s!
} uJ2C+$=Ul
\9&YV;Ct
'p4da2%
System.err.println("文件下载结束！"); BaNU}@
} jM|YW*zNZ
catch(Exception e){e.printStackTrace ();} PM#$H
} %!N2!IiVs
iKR8^sj7S
g_-?h&W
//获得文件长度 ^sr:N5~z`
public long getFileSize() C*Y :w
{ _47j9m]f
int nFileLength = -1; r"HbrQn
try{ X^?|Sz<^E
URL url = new URL(siteInfoBean.getSSiteURL()); 7]<F>97
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vV$hGS(f~
httpConnection.setRequestProperty("User-Agent","NetFox"); =R"Eb1
S)Ub/`f{s
b |o`Q7Hj
int responseCode=httpConnection.getResponseCode(); yg-L^`t+B5
if(responseCode>=400) x mrugNRg
{ WrIL]kJw^
processErrorCode(responseCode); 6Zl.Lh
return -2; //-2 represent access is error i9f7=-[U_
} KoxGxHz^Y3
{="Su{i}}
Ppi-skT
String sHeader; q9g[+*9]$
V'f&JQA
VR5e CJ:i
for(int i=1;;i++) }uV?
{ EL2hD$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YiY&;)w
//Utility.log(in.readLine()); 2Be?5+
sHeader=httpConnection.getHeaderFieldKey(i); JsWq._O{/
if(sHeader!=null) W>t&N
{ 1DI"LIL
if(sHeader.equals("Content-Length")) R9|2&pfm(M
{ 3_R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3<~2"@J
break; QTrlQH&p
} 3& fIO
} /z.7:<gZ(
else {8*d;[X50
break; 'Z(MV&
} Npf7p
} %Mb( c+7
catch(IOException e){e.printStackTrace ();} .5#tB*H
catch(Exception e){e.printStackTrace ();} |R &3/bEr
b0zxT9
+UpMMh q
Utility.log(nFileLength); #sm_.?P
6|"!sW`%N
J4*:.8Ki
return nFileLength; J6^Ct
} JPoK\-9NT
9 z8<[>
i?i7T`
//保存下载信息（文件指针位置） iz%A0Z+`bg
private void write_nPos() #?b^B~ #
{ &[2Ej|o
try{ x(/@Pt2B
output = new DataOutputStream(new FileOutputStream(tmpFile)); SceCucT
output.writeInt(nStartPos.length); 6yl;o_6:
for(int i=0;i<nStartPos.length;i++) )68fm\t(
{ &xiDG=I#
// output.writeLong(nPos); 6Qzu-
output.writeLong(fileSplitterFetch.nStartPos); #pm-nU%|_j
output.writeLong(fileSplitterFetch.nEndPos); *?R\[59
} !=h|&Vta
output.close(); ma]F%E+$
} ~QEXB*X-g'
catch(IOException e){e.printStackTrace ();} 8.;';[
catch(Exception e){e.printStackTrace ();} P9tQS"Rs
} /qz "I-a
|au qj2
>kDdWgRQ
//读取保存的下载信息（文件指针位置） 5[j!\d}U
private void read_nPos() eV{FcJha
{ zcD_}t_K
try{ "<jEI /
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mZ0oa-Iy
int nCount = input.readInt(); %Dr4~7=7a
nStartPos = new long[nCount]; a@_Cx
nEndPos = new long[nCount]; :C:N]6_{SZ
for(int i=0;i<nStartPos.length;i++) >$S,>d_k`
{ yzM+28}L<I
nStartPos = input.readLong(); eE.5zXU3R
nEndPos = input.readLong(); KZ<RDXVT
} )T};Q:
input.close(); cLyuCaH>c
} ]htZ!; 8J
catch(IOException e){e.printStackTrace ();} >%p m"+h{
catch(Exception e){e.printStackTrace ();} 5c}9
} \#+2;L
>*t>U8
<K=B(-~
private void processErrorCode(int nErrorCode) /@nRL
{ 3!oQmG_T
System.err.println("Error Code : " + nErrorCode); ^tKOxW# a
} ?#EXG
J"2ODB5"
FG5c:Ep
//停止文件下载 HT,kx
public void siteStop() h3d\MYO)B
{ g=YiR/O1QN
bStop = true; zyp"*0zUr
for(int i=0;i<nStartPos.length;i++) 72`/xryY
fileSplitterFetch.splitterStop(); [ls ?IFg
xm10
% 6hw
} Y7t{4P
} ME10dr
//负责部分文件的抓取 yDkDtO`K
**FileSplitterFetch.java 61rh\<bn
*/ *"QE1Fum'
package NetFox; >5@vY?QXO
})0 7u
PSQ:'
import java.io.*; `)C`_g3Ew
import java.net.*; CpqSn/
$-9@/%Y
S.F=$z.%
public class FileSplitterFetch extends Thread { (jE:Q2"
whm tEY
-^jLU FC
String sURL; //File URL 1DlcO>#@
long nStartPos; //File Snippet Start Position V-ouIqnI
long nEndPos; //File Snippet End Position ExP25T
int nThreadID; //Thread's ID j]l}K*8(
boolean bDownOver = false; //Downing is over FeeWZe0i
boolean bStop = false; //Stop identical )< a8a@
FileAccessI fileAccessI = null; //File Access interface G*~*2>~
Is6']bYh
^'I5]cRa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M7<#=pX&
{ @oc%4~zl
this.sURL = sURL; ]vkHU6d
this.nStartPos = nStart; .f<VmUca
this.nEndPos = nEnd; fYQi#0drn
nThreadID = id; i`nw"8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ryp$|?ckJ
} #Xw[i
+ZA\M:^b
6BN(^y#-X
public void run() kbT-Oz 2
{ pdha"EV
while(nStartPos < nEndPos && !bStop) OUk5c$M(
{ IZv, Wo
5F sj_wFk
yqb<<4I
try{ Nl<,rD+KSD
URL url = new URL(sURL); ^}7t:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7RFkHME
httpConnection.setRequestProperty("User-Agent","NetFox"); IS 9q 5/]
String sProperty = "bytes="+nStartPos+"-"; p>tdJjnt
httpConnection.setRequestProperty("RANGE",sProperty); ;q&D,4r]
Utility.log(sProperty); $F()`L{Tj
9egaN_K
@bCiaBdi
InputStream input = httpConnection.getInputStream(); 8Pdnw/W
//logResponseHead(httpConnection); rHBjR_L.2
2T%f~yQ^
^?]H$e
byte[] b = new byte[1024]; ftH%, /,
int nRead; TIhzMW\/K
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _%Ld Ez
{ J9=0?^v-:B
nStartPos += fileAccessI.write(b,0,nRead); JIKxY$GS
//if(nThreadID == 1) ZpctsCz]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J'c9577$
} 5"~^;O
HgATH
]bE?n.NwZ
Utility.log("Thread " + nThreadID + " is over!"); !gew;Jz
bDownOver = true; N&h!14]{Z
//nPos = fileAccessI.write (b,0,nRead); 6Oba}`)q9
} 8 (h
catch(Exception e){e.printStackTrace ();} ^QQNJ
} 3X,{9+(F
} OwIy(ukTI
N~J Eia%
6:tr8 X_
//打印回应的头信息 v]U;5Uo
public void logResponseHead(HttpURLConnection con) +vSE}
{ +mOtYfW
for(int i=1;;i++) [IBk-opap
{ KL"L65g&
String header=con.getHeaderFieldKey(i); }/r%~cZ
if(header!=null) U*:'/.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eniR}
Utility.log(header+" : "+con.getHeaderField(header)); AR6vc
else "I FGW4FnL
break; $cU/Im`
} R,+(JgJ
} Byj~\QMD|
-?1J+}?
iPO S
public void splitterStop() 5m?$\h
{ j:KQIwc
bStop = true; gK\7^95
} ZKPkx~,U[
V>92/w.fe
mM{v>Em2K#
} ~Fb?h%w
swL|Ff`$
Qb{5*>
/* 9,eR=M]+:
**FileAccess.java g9Gy3zk=
*//文件访问(定位，写) r$Qh`[<
package NetFox; K)\gbQ|
import java.io.*; m9cT}x&j
r['C.S6
XqH<)B ]
public class FileAccessI implements Serializable{ xumv I{
"1Aus
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8mLU ~P |
RandomAccessFile oSavedFile; 4PM`hc
long nPos; iZ\z!tHR
-JK4-Hg
d( g_y m*
public FileAccessI() throws IOException 7e[\0:Z
{ 1tz .e\
this("",0); 1u+(rVQN
} fGWK&nONyk
T["(YFCByg
P[8N58#
public FileAccessI(String sName,long nPos) throws IOException nn%xN\~<
{ @0'|Uygn
oSavedFile = new RandomAccessFile(sName,"rw"); *7ro [
this.nPos = nPos; ?} tQaj
oSavedFile.seek(nPos); Lta\AN!c
} ye2Oh7
)1 j2
M6#(F7hB
public synchronized int write(byte[] b,int nStart,int nLen) [`\Qte%UH
{ 'FFc"lqj
int n = -1; {o%R~{6
try{ V/}8+Xq
oSavedFile.write(b,nStart,nLen); L(8dK
n = nLen; uI&M|u:nT
} xR`2+t&t
catch(IOException e) jpv,0(
{ E/']M~Q
e.printStackTrace (); >;W(Jb7e
} mDfWR
]t;5kj/
]bweQw@i
return n; X-FHJ4
} #?6RoFgMe
Tj9q(Vq
e*s{/a?,
} \9QOrjiw
V1A3l{>L
-#x\E%v.F
/* .y+U7"?s*
**SiteInfoBean.java ),,vu
*/ 5-^twXC&
package NetFox; H]X)@n>
EPy/6-5b
hGV/P94
public class SiteInfoBean { Q#KjX;No
4/>={4Y9
lej{VcG
private String sSiteURL; //Site's URL ow[qpP[
private String sFilePath; //Saved File's Path p]4 sN
private String sFileName; //Saved File's Name 3IFU{0a`
private int nSplitter; //Count of Splited Downloading File UI;{3Bn
Lai"D[N
Shz;)0To
public SiteInfoBean() 90}B*3x
{//nSplitter的缺省值为5 F9W5x=EK\
//default value of nSplitter is 5 a~>h'}C>
this("","","",5); :6V8
} Q>$L;1E*,
]EQ/*ct
yk2j&}M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N<99K!
{ Z]BRMx
sSiteURL= sURL; gBu4`M
sFilePath = sPath; ? Q}{&J
sFileName = sName; VIzZmd
this.nSplitter = nSpiltter; q?&&:.H"?5
rI/KrBM
YyIt-fPZ
} %>TdTt
`l#g`~L
8t%1x|!
public String getSSiteURL() K>y+3HN[6
{ <H6Uo#ao
return sSiteURL; K#r`^aUc
} E"=$p$k
Sdp1h0E}7=
M.xEiHz
public void setSSiteURL(String value) cqudF=q
{ rY}ofq7b
sSiteURL = value; p~IvkW>ln)
} fF%r$`2
jQ*Qh
`2B+8,{%
public String getSFilePath() BxF
{ dp_q:P4;B
return sFilePath; ZV;yXLx|
} g 7X>i:
|:z%7J3wP
Yo:&\a K[
public void setSFilePath(String value) tPsU7bFk
{ odDt.gQXU
sFilePath = value; DxHeZQ"LL
} 7f>n`nq?
rtm28|0H'
qb&*,zN
public String getSFileName() t At+5H
{ kWFR(J&R
return sFileName; Lrq&k40y
} V EzIWNV
o;fQ,rP%
^-ZqS
public void setSFileName(String value) o/R-1\Dn
{ Wm61
sFileName = value; s/V[tEC*z
} t&_lpffv
^gG,}GTl
3$Je,|bs
public int getNSplitter() Vs >1%$If
{ i^#RiCeo
return nSplitter; UWI5/R
} =E}/Z
_EP}el
@ 55Y2
public void setNSplitter(int nCount) %:lQ ~yn
{ V6Y!0,w!a
nSplitter = nCount; bGZy0.
} L6T_&AiL$
} aC*J=_9o#
n" sGI
<d4^gAfs*
/* *d(Dk*(
**Utility.java ScEM#9T|
*/ Z_%>yqDC
package NetFox; Wxjpe4
]P.S5s'
*h UrE
public class Utility { 8QU`SoS9
~0L>l J
JmkJ^-A 6
public Utility() d=[.
{ @ o]F~x
c c:xT0Y
\gdd
} Z,*VRuA
; ?!sU
//线程睡眠 OX91b<A
public static void sleep(int nSecond) nP.d5%E
{ 3hkA`YSYt
try{ piU4%EO
Thread.sleep(nSecond); ,M9'S;&^
} I/'>Bn+
catch(Exception e) . @.CQB=E
{ 0/c4%+ Ln
e.printStackTrace (); !|D,cs
} $/Mk.(3'P
} ~34$D],D
QeGU]WU{
//日志 1z)+P1nH]
public static void log(String sMsg) 6(.&y;
{ -szvO_UP
System.err.println(sMsg); =3FXU{"Qi4
} <R2bz1!h.
LTxOq|/Cq
d97wiE/i<
public static void log(int sMsg) 5QlJX
{ grZN.zTO
System.err.println(sMsg); yt?#T#
} X]N8'Yt
} h<?Vzl
kHJjdgV
bcQ$S;U)
/* kY|<1Ht
**TestMethod.java {2!.3<#
*/ (q)W<GYP
package NetFox; @ ~PL|Pp_
Ba"Z^(:
t ,0~5>5
public class TestMethod { g%K3ah v
JWLQ9UX
;(z0r_p<q
public TestMethod() wDn5|F}i&
{ ///xx/weblogic60b2_win.exe "F=O
try{ _]B'C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'E9\V\bi
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .^/OL}/~<
SiteFileFetch fileFetch = new SiteFileFetch(bean); ss*dM.b
fileFetch.start(); STO6cNi
} 'Ic$p>
catch(Exception e){e.printStackTrace ();} 'C(YUlT2?P
X4jtti
#U^@)g6
} X"yLo8y8$
dD=dPi#
q?`bu:yS
public static void main(String[] args) bEM-^SR
{ h9No'!'!
new TestMethod(); O`*}N1No[
} *edB3!!
} ondF
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