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)); s\'y-UITi1
} p)B33ZzC
for(int i=0;i<nEndPos.length-1;i++) 6a4'xq7
{ *Y85DEA
nEndPos = nStartPos[i+1]; )jyq{Jb
} O^9CV*]!n
nEndPos[nEndPos.length-1] = nFileLength; zL:&Q<
} jR{-
} Rx6l|'e
TB7>s~)47E
gq'>6vOj
//启动子线程 _wf5%(~b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j G-
for(int i=0;i<nStartPos.length;i++) I|,pE**T
{ Y5dD|]F|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]} 61vV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q$r&4s)To
nStartPos,nEndPos,i); sl/=g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #D+7TWDwNt
fileSplitterFetch.start(); U;xu/xDRi
} @#RuSc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rn`ld@=p[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'lJEHz\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?X\3&Ujy$
nEndPos = " + nFileLength); `|$'g^eCL
// fileSplitterFetch[nPos.length-1].start(); {5^K Xj$B
\6{krn|
qysTjGwa]
//等待子线程结束 9-0<*)"b>
//int count = 0; *~p(GC
//是否结束while循环 :e*DTVv8
boolean breakWhile = false; 8b|OXWl
u!Xb?:3uj
& _; y.!
while(!bStop) 2w+U$6e C
{ lnS(&`oh\=
write_nPos(); xfjd5J7'
Utility.sleep(500); #/Ruz'H1>
breakWhile = true; vr=~M?
lDN"atSf
A)tP()+)
for(int i=0;i<nStartPos.length;i++) w|IjQ1{
{ ! Tx&vtq
if(!fileSplitterFetch.bDownOver) TZ[Zm
{ bS.s?a
breakWhile = false; 33Jd!orXU
break; JVtQ,oZ
} =#qZ3 Qz_
} &FSmqE;@^
if(breakWhile) "~F3*lk#E
break; <5S@ORN
k<a;[_S
.evbE O5
//count++; |EKu2We*
//if(count>4) E<tK4?i"
// siteStop(); =;0wFwSz
} !b8uLjd;
YEv%C|l
<$%X<sDkq
System.err.println("文件下载结束！"); -$(Jk<
} jMM$d,7B
catch(Exception e){e.printStackTrace ();} E@-ta):
} bLzs?eos
8WL8/
+#2)kg 9_
//获得文件长度 ~ 3^='o
public long getFileSize() ]hA,LY f
{ LxLy+yC#p
int nFileLength = -1; `K*b?:0lp
try{ B z^|SkEit
URL url = new URL(siteInfoBean.getSSiteURL()); q2hFOm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %SrM|&[
httpConnection.setRequestProperty("User-Agent","NetFox"); M|q~6oM
#]CFA9z
+Y}V3(w9X
int responseCode=httpConnection.getResponseCode(); `ltN,?/
if(responseCode>=400) <Mx0\b!
{ [}OgSP9i
processErrorCode(responseCode); ndink$
return -2; //-2 represent access is error F>zl9Vi<
} rYY$wA@
LCs__.
$Az^Y0[D
String sHeader; 'fx UV<K&
9i5tVOhE
K{@3\5<
for(int i=1;;i++) N|mJg[j@7
{ (hB?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "9IYB)Js
//Utility.log(in.readLine()); (-0ePSOG
sHeader=httpConnection.getHeaderFieldKey(i); ZrO!L_/
if(sHeader!=null) +x=)/;:
{ ?^i1_v7 Bi
if(sHeader.equals("Content-Length")) 0V$k7H$Z
{ k'T^dY&c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :Zt2'vcGpf
break; +-<}+8G;
} z0%\OhuCcf
} iYJZvN
else F(5hmr
break; /P:.qtT(
} -`b8T0?oK
} `Out(Hn
catch(IOException e){e.printStackTrace ();} IvHh4DU3Z
catch(Exception e){e.printStackTrace ();} =-KMb`xT
8j5<6Cv_
/ASaB
Utility.log(nFileLength); E<E3&;qD
HDVW0QaMu
Z(u5$<up
return nFileLength; ~YP Jez
} X(A.X:"
#m<tJnEO
M;w?[yEZ
//保存下载信息（文件指针位置） :~F:/5
private void write_nPos() 59r_#(uo
{ K+Y^>N4m
try{ -d+aV1n
output = new DataOutputStream(new FileOutputStream(tmpFile)); oVvc?P
output.writeInt(nStartPos.length); h.eM RdlO
for(int i=0;i<nStartPos.length;i++) @L/o\pvc
{ @I`C#~
// output.writeLong(nPos); vI1i,x#i
output.writeLong(fileSplitterFetch.nStartPos); ^EELaG
output.writeLong(fileSplitterFetch.nEndPos); "9!d]2.-Vk
} 2I/xJ+
output.close(); $e1=xSQp4
} S4UM|`
catch(IOException e){e.printStackTrace ();} t5B7I59
catch(Exception e){e.printStackTrace ();} 1'.7_EQ4T
} 2P#=a?~[
#KxbM-1=
g.py+ ZFJ
//读取保存的下载信息（文件指针位置） [XVEBA4GI
private void read_nPos() wh6yPVVF/
{ Q=mI9
try{ _"@CGXu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `x8J
int nCount = input.readInt(); 'e)^m}:?D
nStartPos = new long[nCount]; j/`94'Y
nEndPos = new long[nCount]; dU)]:>Uz
for(int i=0;i<nStartPos.length;i++) H}hFFI)#Oo
{ :bu>],d-8'
nStartPos = input.readLong(); &;yH@@Z
nEndPos = input.readLong(); b[9&l|y^
} /X"/ha!=&D
input.close(); qfY5Ww$8
} o+w;PP)+=
catch(IOException e){e.printStackTrace ();} Zxr!:t7
catch(Exception e){e.printStackTrace ();} Fm\"{)V:b
} in+}/mwfC
b-ll
fmqb`%
private void processErrorCode(int nErrorCode) v ^[39*8
{ F{06 _T
System.err.println("Error Code : " + nErrorCode); sUZX }
} ;~fT,7qBah
[.se|]t7X
Od+6 -J
//停止文件下载 PZxAH9 S?
public void siteStop() <+MyZM(z>
{ -fhN"B)
bStop = true; L`f^y;Y.
for(int i=0;i<nStartPos.length;i++) 5oEV-6
fileSplitterFetch.splitterStop(); o#) {1<0vg
}En
!+>v[(OzM
} qm/Q65>E
} :NJ_n6E
//负责部分文件的抓取 pl@O N"=[
**FileSplitterFetch.java NBl+_/2'w
*/ )?+$x[f!*
package NetFox; 1b=lpw1}
oSiMpQu08
|4$M]Mf0
import java.io.*; b@RHc!,>jV
import java.net.*; `&\Q +W
X%z }VA
+$4(zPs@
public class FileSplitterFetch extends Thread { L,y6^J!
8n1'x;
!cKz7?w
String sURL; //File URL =qN2Xg/
long nStartPos; //File Snippet Start Position rpeJkG@+
long nEndPos; //File Snippet End Position SJD@&m%?[
int nThreadID; //Thread's ID u\&b4=nL
boolean bDownOver = false; //Downing is over P96pm6H_;
boolean bStop = false; //Stop identical +]=e;LN$0
FileAccessI fileAccessI = null; //File Access interface zvABU+{jD
fYKOJ5f
`:N# 'i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .MO\uh0N
{ B8E'ddUw
this.sURL = sURL; 4iSa7YqhBT
this.nStartPos = nStart; n]8<DX99Q0
this.nEndPos = nEnd; %X#zj"
nThreadID = id; :#dE:L;T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2,ECYie^
} \RNg|G
/Mb"V5S(W
_|h8q-[3
public void run() oIUy-|
{ U(~+o
while(nStartPos < nEndPos && !bStop) 8r3A~
{ Ol4+_n8xj
2WUT/{:X
Uj&W<'I
try{ xsWur(>]
URL url = new URL(sURL); ~?B;!Csk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'SQG>F Uy
httpConnection.setRequestProperty("User-Agent","NetFox"); (sVi\R
String sProperty = "bytes="+nStartPos+"-"; nUkaz*4qU
httpConnection.setRequestProperty("RANGE",sProperty); f~}H
Utility.log(sProperty); !i=nSqW
9UvXC)R1
eQQ>
InputStream input = httpConnection.getInputStream(); ^CwR!I.D}4
//logResponseHead(httpConnection); wAnb Di{W
!w&kyW?e
2^?:&1:
byte[] b = new byte[1024]; apE
int nRead; n3J53| %v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cwGbSW$t
{ NcY608C
nStartPos += fileAccessI.write(b,0,nRead); }9nDo*A"}
//if(nThreadID == 1) AT5aDEb^^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c-.t>r&
} $-[CG7VgX%
M'_9A
Tw +
Utility.log("Thread " + nThreadID + " is over!"); `xrmT t X
bDownOver = true; 5dZ|!
//nPos = fileAccessI.write (b,0,nRead); 1sYEZO;
} odIZo|dv
catch(Exception e){e.printStackTrace ();} 42]pYm(jk3
} ?-1r$31p
} &=4(l|wcg
DBLO|&2!z[
JEE{QjTh
//打印回应的头信息 fGmT_C0t
public void logResponseHead(HttpURLConnection con) CbN!1E6).
{ *Q1~S]g
for(int i=1;;i++) ]9\!;Bz^J
{ P./VmY'
String header=con.getHeaderFieldKey(i); c6Y\n%d&
if(header!=null) ;NNe!}C
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kI%%i>Y}
Utility.log(header+" : "+con.getHeaderField(header)); \>Efd
else (Vo>e =q
break; 7Pa@1']
} A&>.74}p
} V2N_8)s9W
L/"0ws_
LzYO$Ir:g
public void splitterStop() >0l"P"]
{ !ti6
bStop = true; id$Ul?z8
} 02Ia2e.f
L\;6y*K
&N3Y|2
} VN%INUi@
gzeQ|m2]
>MPr=W%E
/* g[w,!F
**FileAccess.java Z}-Vf$O~
*//文件访问(定位，写) JMTvSXr
package NetFox; -j&Tc`j_
import java.io.*; ['ksP-=
KoS*0U<g6
5O`dO9g}$
public class FileAccessI implements Serializable{ Hk|0HL
$-On~u0g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8XsguC
RandomAccessFile oSavedFile; &d'Awvy0
long nPos; &N;-J2M
0q&'(-{s1
><=gV~7lx
public FileAccessI() throws IOException 1 E22R
{ eAqz3#_My
this("",0); l&}y/t4%
} v(pmIb{
]^6c8sgnR
;U_QvN|
public FileAccessI(String sName,long nPos) throws IOException +S=Rn,
{ w^]6w\p
oSavedFile = new RandomAccessFile(sName,"rw"); UQ4% Xp
this.nPos = nPos; nJ" '
oSavedFile.seek(nPos); w4fW<ISg
} ;*,f<
not YeY7wR
~,2/JDVJ5-
public synchronized int write(byte[] b,int nStart,int nLen) wfjnA~1h
{ fK(}Ce
int n = -1; #0Tq=:AE>
try{ Bphof0{<}
oSavedFile.write(b,nStart,nLen); #Z5}2soA
n = nLen; Iuh/I +[7
} c*R/]Dn
catch(IOException e) ?Mee 6
{ 'FYJMIs
e.printStackTrace (); *s;|T?~i
} O2"gj"D
vp.ZK[/`
O-4C+?V
return n; ){Ob,LEU&
} "kc/J*u-3
M|] "W
Ka`=WeJ|
} Yf[Qtmh]I
M5x U9]B
>fIk;6<{
/* mJM_2Ab
**SiteInfoBean.java B7z -7&TE
*/ ^H6<Km l/V
package NetFox; V=1Bo~
hxS 6:5Uc
R-P-i0~
public class SiteInfoBean { K+6e?5t
:g.46dp4
Sua[O$
private String sSiteURL; //Site's URL +\r+n~w
private String sFilePath; //Saved File's Path 1J'3g
private String sFileName; //Saved File's Name "al`$%(
private int nSplitter; //Count of Splited Downloading File }E_#k]#*
\8uIER5)
)+Oujt
public SiteInfoBean() U#1bp}y
{//nSplitter的缺省值为5 0T>H)c6:\
//default value of nSplitter is 5 72veLB
this("","","",5); 5 B=^v#m
} P#:?ok
wRrnniqf8
3T&6opaF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?^j^K-rx
{ $u/E\l
sSiteURL= sURL; +NFzSal
sFilePath = sPath; z;u
sFileName = sName; %4W$Lq}
this.nSplitter = nSpiltter; V:G>G'Eh0
P<fnLQ9
Q%-di=
} R-:fd!3oQ
lb:/EUd5
RNQK
public String getSSiteURL() hTbI -u7BF
{ !'Q -yoHKD
return sSiteURL; |A8/FU2{
} WF\)fc#;_o
ZR\VCVH\^
21(p|`X
public void setSSiteURL(String value) sFBneBub
{ &[hLzlrg
sSiteURL = value; vp(;W,ba:|
} #b7$TV
wR{'y)$
wW"z
public String getSFilePath() ,<:!NF9
{ 3R&lqxhg
return sFilePath; _`#3f1F@[
} 1xc~`~
yObuWDA9
b}Zd)2G
public void setSFilePath(String value) ".dZn6"mI
{ z%/N!RLW
sFilePath = value; smm]6
} ]!IVz)<E&
}(<%`G6N
hb{u'=
public String getSFileName() 1EyL#;k
{ N 75:5
return sFileName; `EtS!zD~b
} V_Wwrhua
#6!52
V#jWege
public void setSFileName(String value) F_bF
{ .I@CS>j
sFileName = value; H}LS??P
} .6OgO{P:
!d&C>7nb
.SWt3|Pi5
public int getNSplitter() 2y%,p{="
{ fBQ?|~:n
return nSplitter; 7u[j/l,
} s[gKc'
phE &7*!Q
FW"^99mrnb
public void setNSplitter(int nCount) "6a8s;
{ W(hMft%
nSplitter = nCount; vLxQ *50v$
} r",]Voibd
} c/5W4_J
xm6EKp:
F:#J:x'
/* oDcKtB+2
**Utility.java ?:Y#Tbi3
*/ S!{t6'8K
package NetFox; 8?Z4-6!{V,
+w8R!jdA
x3rlJs`$;
public class Utility { 8t=(,^c
_ %%Z6x(
*6U&Qy-M
public Utility() IHp_A
{ A6oq.I0
G Xt4j
uGs;}<<8
} ~r{5`;c
}Yv\0\~'W|
//线程睡眠 Bb{!Yh].:A
public static void sleep(int nSecond) {_U Kttp
{ it2 a
try{ 0[<~?`:)
Thread.sleep(nSecond); oQ=>'w
} c)&>$S8*
catch(Exception e) 4'p=p#o
{ )fdE6
e.printStackTrace (); VGqa)ri"
} irk*~k ?
} IcIOC8WC
*1@:'rJ
//日志 C>Is1i^9
public static void log(String sMsg) |Oag,o"
{ dO7;}>F$n
System.err.println(sMsg); _IeU+tS
} ?GBkqQ
joul<t-
gh6d&ucQ^
public static void log(int sMsg) !AJ]j|@VBd
{ Npn=cLC&
System.err.println(sMsg); H.G!A6bd
} KLC{7"6e)
} TzBzEiANn
2l5KJlfj>k
c<#<k}y
/* nY $tp
**TestMethod.java iq*A("pU
*/ UofTll)
package NetFox; ^zEE6i
7~M<cD
eo^/c+FG
public class TestMethod { $j)hNWI
2AVc? 9@
XN,,cU
public TestMethod() F^!mI7Z|(2
{ ///xx/weblogic60b2_win.exe mKq"34F
try{ *^ \FIUd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2i|B=D(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]IJv-(
SiteFileFetch fileFetch = new SiteFileFetch(bean); mDFlz1J,e
fileFetch.start(); Ri>?KrQF%
} `:M^8SYrL
catch(Exception e){e.printStackTrace ();} "8V{5e!%j'
V,%L~dI
djT5X
} d77r9
-v?hqWMp#
7t-Lz| $"
public static void main(String[] args) }%{MPqg
{ NN 0Q`r,8}
new TestMethod(); r+<{S\ Q
} si(;y](
} uHNpfKnZ
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