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)); x21dku<6K[
} V f-a'K&
for(int i=0;i<nEndPos.length-1;i++) eh1Q7~
{ %WqNiF0-
nEndPos = nStartPos[i+1]; 1qV@qz
} ThPE 0V
nEndPos[nEndPos.length-1] = nFileLength; S'oGt&Z<
} =rdY @
} 7t,t`
+,~zWv1v
r=yK,d/1
//启动子线程 .jy]8S8[|%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *'ZB*>
for(int i=0;i<nStartPos.length;i++) .NtbL./=|
{ *6xgctk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .]aF 1}AI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OL_{_K(w
nStartPos,nEndPos,i); uKgZ$-'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5[j`6l
fileSplitterFetch.start(); T~h5B(J;
} "c}@V*cO<d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5*[2yKsTi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7ugZE93!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O;7)Hjwt
nEndPos = " + nFileLength); &uC@|dbC5
// fileSplitterFetch[nPos.length-1].start(); [AV4m
eNiaM6(J
jA#/Z
//等待子线程结束 ?\8?%Qk
//int count = 0; j~j\\Y
//是否结束while循环 hHqh{:q{v
boolean breakWhile = false; Kx_h1{
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wP,JjPUt
while(!bStop) fDx9iHGv
{ nx0K$Ptq
write_nPos(); +cU>k}
Utility.sleep(500); qRbf2;
breakWhile = true; h*u`X>!!
;gC|
fwzb!"!.@
for(int i=0;i<nStartPos.length;i++) AkOO)0
{ \.mI
if(!fileSplitterFetch.bDownOver) $%VuSrZ&
{ Qp`gswvE
breakWhile = false; Xl74@wq
break; 9'hv%A:\3
} };'\~g,1
} nC{%quwh{
if(breakWhile) Zw wqSyuGf
break; #97h6m?
Fs[aa#v4B
VbBPB5 $q
//count++; &~CY]PN.
//if(count>4) B c2p(z4
// siteStop(); >vo=]cw
} l7De6A"
Fd*8N8Pi
M:5b4$Qh<
System.err.println("文件下载结束！"); C*nB
} }MUn/ [x
catch(Exception e){e.printStackTrace ();} If%/3UJ@
} Z4IgBn(Z_}
'=P7""mN5
%,ngRYxT#
//获得文件长度 Le%ZV%,
public long getFileSize() F:mq'<Q
{ 0Ia($.1mY
int nFileLength = -1; q\H[am
try{ ,]b~t0|B
URL url = new URL(siteInfoBean.getSSiteURL()); k%^lF?_0I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +VQ\mA59
httpConnection.setRequestProperty("User-Agent","NetFox"); )& u5IA(
-(K9s!C!.
~)(\6^&=|
int responseCode=httpConnection.getResponseCode(); QNDHOo>v
if(responseCode>=400) Hr$QLtr
{ "Ky; a?Y
processErrorCode(responseCode); h,"4SSL
return -2; //-2 represent access is error 1{P'7IEj
} tnLAJ+-M
F`9]=T0
$/nY5[
String sHeader; |^@dFOz
ul*Qt}
)Pv9_XKJ
for(int i=1;;i++) }pJwj
{ P (S>=,Y&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YtO|D
//Utility.log(in.readLine()); 'fPdpnJ<
sHeader=httpConnection.getHeaderFieldKey(i); r[K5w
if(sHeader!=null) MX+Z ?
{ |\n_OS7
if(sHeader.equals("Content-Length")) w|Nz_3tI
{ In[Cr/&/Y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #h/Mbj~S
break; )XWP\ h
} Zkf0p9h\
} DfKr[cqLM
else `7H4Y&E
break; yeHDa+}
} VWO9=A*Y|
} o: ;"w"G
catch(IOException e){e.printStackTrace ();} ;,]P=Ey
catch(Exception e){e.printStackTrace ();} zz& ?{vJ
)Y)pmjZaG
xpOg8u5
Utility.log(nFileLength); }K3x
>a}f{\Q
<vwkjCA`
return nFileLength; Onwp-!!.
} @Pt="*g
GH[wv<
]7e =fM9V;
//保存下载信息（文件指针位置） hqRw^2F
private void write_nPos() 6"}?.E$
{ be +4junf
try{ +a*tO@HG
output = new DataOutputStream(new FileOutputStream(tmpFile)); "Y\_TtY
output.writeInt(nStartPos.length); #UbF9})q
for(int i=0;i<nStartPos.length;i++) cH>%r^G\
{ R+CM`4CD
// output.writeLong(nPos); O|w J)
output.writeLong(fileSplitterFetch.nStartPos); KIWe@e
output.writeLong(fileSplitterFetch.nEndPos); %dY<=x#b
} xNbPsoK
output.close(); &iV,W4
} o^ XtU5SVq
catch(IOException e){e.printStackTrace ();} []D@Q+1
catch(Exception e){e.printStackTrace ();} [p<w._b i
} ^yOZArc'r
4R\Hpt
\eFR(gO+
//读取保存的下载信息（文件指针位置） [Jv@J\
private void read_nPos() _8E/)M
{ N ,z6y5Lu
try{ >vA2A1WhW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Jkek-m
int nCount = input.readInt(); pxa(
nStartPos = new long[nCount]; 4]E3cAJ
nEndPos = new long[nCount]; F>rH^F
for(int i=0;i<nStartPos.length;i++) e2A-;4?_
{ ,2W8=ON
nStartPos = input.readLong(); rvw)-=qR[
nEndPos = input.readLong(); hvaSH69*m
} 5;HH4?]p
input.close(); Gy(=706
} |vw"[7_aS
catch(IOException e){e.printStackTrace ();} /gG"v5]
catch(Exception e){e.printStackTrace ();} )-._FOZ6
} O<V4HUW
^(FdXGs[
15sp|$&`
private void processErrorCode(int nErrorCode) /~<@*-'
{ |)*fRL,
System.err.println("Error Code : " + nErrorCode); q*9!,!e
} aca=yDs2
o !U 6?
}B1!gz$YNO
//停止文件下载 ,l)^Ft`5
public void siteStop() Ct>GYk$
{ UNBH
bStop = true; mrjswF27$o
for(int i=0;i<nStartPos.length;i++) g?ULWeZg5
fileSplitterFetch.splitterStop(); _D+J!f^
X93!bB
d}4Y(
} ZEx}$<)_
} % S os
//负责部分文件的抓取 <q@a~'Ai?!
**FileSplitterFetch.java sL$:"=
*/ )<tI!I][j
package NetFox; S@/IQR
H7DJ~z~J
mVpMh#zw
import java.io.*; Sb82}$sO
import java.net.*; {.INnFGP@)
Qr{E[6
@nCd
public class FileSplitterFetch extends Thread { +csi[c)3E
:w^Ed%>y7
#e$5d>j(
String sURL; //File URL *vwbgJG! *
long nStartPos; //File Snippet Start Position W}mn}gTQ
long nEndPos; //File Snippet End Position >: g3k
int nThreadID; //Thread's ID R)m'lMi|
boolean bDownOver = false; //Downing is over \r+8qC[,
boolean bStop = false; //Stop identical +O?KNZ
FileAccessI fileAccessI = null; //File Access interface 7](KV"%V
Xx>X5Fy
pWJFz-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V: TM]
{ L bmawi^
this.sURL = sURL; JVSA&c%3
this.nStartPos = nStart; VG ;kPzze
this.nEndPos = nEnd; W~7A+=&
nThreadID = id; XLrwxj0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }*S `qW;B
} yvO{:B8%
|M,iM]
#6HA\dE
public void run() t,+nQ9
{ )u`[6,d
while(nStartPos < nEndPos && !bStop) 85Otss/mM
{ y1+*6|
z?*w8kU&>
N@Uy=?)ZJ
try{ ?b>,9A.Z
URL url = new URL(sURL); IHv[v*4:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9^#c| 0T
httpConnection.setRequestProperty("User-Agent","NetFox"); 7%|~>
String sProperty = "bytes="+nStartPos+"-"; Eu@huN*/
httpConnection.setRequestProperty("RANGE",sProperty); Oagsoik
Utility.log(sProperty); c2'Lfgx4
&keR~~/
2Tp1n8FV
InputStream input = httpConnection.getInputStream(); M:[ %[+6
//logResponseHead(httpConnection); I7n"&{s"*
(<xfCH F5
+{f:cea (1
byte[] b = new byte[1024]; @a0DT=>dT
int nRead; po2!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &&8IU;J
{ ,NyY>~+
nStartPos += fileAccessI.write(b,0,nRead); Gsq00j &<Z
//if(nThreadID == 1) 2Ay*kmW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tnN.:%mZ
} nz=GlO'[
wc}5m Hs
E%,^Yvh/
Utility.log("Thread " + nThreadID + " is over!"); FE (ev 9@
bDownOver = true; i/`m`qdg
//nPos = fileAccessI.write (b,0,nRead); #Oc] @
} j2StXq3
catch(Exception e){e.printStackTrace ();} keX,d#
} ?IqQ-C)6D
} OuID%p"O
ogHCt{'
fPR1f~r
//打印回应的头信息 `tA" }1;ka
public void logResponseHead(HttpURLConnection con) "8x8UgG
{ iXVe.n
for(int i=1;;i++) 1AM!8VR2
{ $!-c-0ub
String header=con.getHeaderFieldKey(i); R6kD=JY/!
if(header!=null) r")`Ph@yp
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "!ug_'VW
Utility.log(header+" : "+con.getHeaderField(header)); [6%VRqY
else ^cP!\E-^
break; ;Q OBBF3HG
} g"p%C:NN
} 4~Vx3gEV:
=JK@z
g9}DnCT*.
public void splitterStop() /_AnP
{ 4C61GB?Vy
bStop = true; NV72
} z<U-#k7nz
ORHp$Un~)
?mFv0_!O
} "4+&-ms
"/3'XOK|
@s ?
/* 5HkKurab
**FileAccess.java 5 ZGNz1)?V
*//文件访问(定位，写) jjw`Dto&
package NetFox; }@'$b<!B
import java.io.*; ]6(N@RC
.f%fHj
bpJ(XN}E
public class FileAccessI implements Serializable{ ;g5m0l5
-:Da&V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0WZ_7C?
RandomAccessFile oSavedFile; -Ta9 pxZk
long nPos; Xqg@ e:g
Ce9|=Jx!
hV8[@&Sx3
public FileAccessI() throws IOException B%)%
{ O`x;,6Vr
this("",0); 1PVtxL?1P
} xW)2<m6C&
;qafT@ }C
.h@rLorm>
public FileAccessI(String sName,long nPos) throws IOException "7'J&^|
{ R_W+Ylob
oSavedFile = new RandomAccessFile(sName,"rw"); n'wU;!W9
this.nPos = nPos; =n5zM._S-
oSavedFile.seek(nPos); 8_BV:o9kL
} J>wt(] y
NO "xL,
F\JM\{&F
public synchronized int write(byte[] b,int nStart,int nLen) #>b3"[ |
{ Neq+16*u
int n = -1; I5 o)_nc
try{ TJ_$vI
oSavedFile.write(b,nStart,nLen); X^}I-M%{m
n = nLen; ,<n}W+3
} @r/#-?W
catch(IOException e) :)wy.r;N
{ bf ]f=;.+
e.printStackTrace (); #^lL5=
} QUq_:t+Dv
L[oui,}_
D.B.7-_8
return n; s@&`f{
} rdl;M>0@
y I HXg#
AK,J7
} Su 586;\
c]x1HvPE
#|Y5,a,{
/* Ygm`ZA y
**SiteInfoBean.java a,@]8r-"
*/ >:AARx%
package NetFox; XX7{-Yy
{@H6HqD
.*@;@06?
public class SiteInfoBean { FOv=!'So
*W4m3Lq
9_# >aOqL
private String sSiteURL; //Site's URL 7`-Zuf
private String sFilePath; //Saved File's Path J`peX0Stl
private String sFileName; //Saved File's Name 3 R=,1<
private int nSplitter; //Count of Splited Downloading File `YFtL
4x{0iav
~bM4[*Q7
public SiteInfoBean() oRm L {UDZ
{//nSplitter的缺省值为5 0LPig[
//default value of nSplitter is 5 9oyE$S h]
this("","","",5); ?J%1#1L"/
} %q/62f7?
V/%>4GYnC
oibsh(J3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oI0M%/aM
{ [>+4^&
sSiteURL= sURL; s`M9
sFilePath = sPath; aXQnZ+2e^R
sFileName = sName; d?s<2RkPT
this.nSplitter = nSpiltter; ~ZmN44?R
-E^vLB)O
bx#>BK!
} o1-m1<ft
3B1XZm
#ZJ _T`l
public String getSSiteURL() h%o%fH&F!
{ 3AHlSX
return sSiteURL; G! ]k#.^A,
} K#%&0D!
sd,J3
$h2){*5E{
public void setSSiteURL(String value) mPOGidxix
{ K{x\4
sSiteURL = value; ~xA-V4.
} o9|nJ;
X^T:8npxt
;9[fonk
public String getSFilePath() jlkmLcpf
{ o>).Cj
return sFilePath; zjJ *n8l
} 9E zj"
6TQoqH8@U
UR%/MV
public void setSFilePath(String value) ?+_Gs;DGVE
{ txJr;
sFilePath = value; 8e*,jH3
} ,p4&g)o
2"0es40;0
7FzA*
public String getSFileName() t|H^`Cv6
{ x^HGVWw_
return sFileName; SFB~ ->db
} hU(umL<
:V1W/c
"8c@sHk(w
public void setSFileName(String value) "w^!/
{ #D<C )Q
sFileName = value; bP8Sj16q
} O;z,qo X
~rlB'8j(
~?D4[D|sB
public int getNSplitter() 9)y/:sO<P
{ _76PIR{an
return nSplitter; Ozw;(fDaU
} t`WB;o!
NhfJ30~
rx $mk
public void setNSplitter(int nCount) r#+d&.|
{ zAK+8{,
nSplitter = nCount; {!.(7wV\
} 4zASMu
} 2>|dF~"
L; T8?+x
o4`hY/<t
/* ,oN8HpGs
**Utility.java N96jJk
*/ )i~cr2Hk
package NetFox; <A<{,:5C
tkVbo.[8K
wmk *h-
public class Utility { O#x*iI%
l\BVS)
8yRJD[/S
public Utility() 3t`P@nL0;
{ P::TO-C
CEXyrs<
/,1D)0
} =CK4.
<DMl<KZ
//线程睡眠 *7*lE"$p
public static void sleep(int nSecond) *n;!G8\
{ kv8Fko
try{ 9)0D~oUi
Thread.sleep(nSecond); `kOD[*
} Yb:\a/ y
catch(Exception e) @_U;9)
{ ~oI1zNz/
e.printStackTrace (); bIGHGd
} {xwm^p(f
} Uh.oErHQD
[!!o-9b
//日志 |w_7_J2
public static void log(String sMsg) i7]4W
{ Ol1e/Wv
System.err.println(sMsg); 9w"h
} #@^t;)|
h lkn%
W;_nK4$%'
public static void log(int sMsg) q/4YS0CqE
{ I*LknU@
System.err.println(sMsg); k:*S&$S!E
} -9"['-WH,
} 'I_Qb$
0zo?eI
9dFy"yxYa
/* +cIUGFp}
**TestMethod.java k9)jjR*XxG
*/ 6Pnk5ps }h
package NetFox; < XP9@t&
'pm2n0
P9=?zh6G.
public class TestMethod { W)9K`hM6
d_4T}%q
Vm%1> '&
public TestMethod() $P>`m$(8
{ ///xx/weblogic60b2_win.exe ${+ @gJ+S
try{ 7#@cz5Su
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9[1`jtm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3mYiQ2
SiteFileFetch fileFetch = new SiteFileFetch(bean); gfsI6/Y
fileFetch.start(); EG0WoUX|
} u1t%(_h
catch(Exception e){e.printStackTrace ();} L~(_x"uXd
Ae69>bkE0
r;>*_Oc7g
} $}lbT15a
t>1Z\lE\"
=3q/F7-
public static void main(String[] args) jZh';M8"
{ R16'?,
new TestMethod(); XpmS{nb
} bA= |_Wt
} (:._"jp]
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