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)); bGOOC?[UX
} ztTj2M"
for(int i=0;i<nEndPos.length-1;i++) 1PpZ*YK3z
{ :m]~o3KRy
nEndPos = nStartPos[i+1]; u,AP$+Qk
} ukpbx;O:hc
nEndPos[nEndPos.length-1] = nFileLength; n^B9Mh@
} >lQ@" U
} ~U(`XvR\4
4~xKW2*`K
:7UC=GKQk
//启动子线程 k#uSH eq7f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o}$uP5M8q
for(int i=0;i<nStartPos.length;i++) {L~j;p_G&
{ p.6C.2q~s]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m0QE S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <}t~^E,
nStartPos,nEndPos,i); 39to5s,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uzg(C#sp
fileSplitterFetch.start(); Su?e\7aj
} dp#JvZb
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (VDY]Q)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yJQ>u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %]7'2
nEndPos = " + nFileLength); K+MSjQS"
// fileSplitterFetch[nPos.length-1].start(); 'yxN1JF
k%uR!cL
EyR~VKbJ'
//等待子线程结束 Ipro6 I
//int count = 0; m}A|W[p<
//是否结束while循环 \ vn!SO7
boolean breakWhile = false; )U12Rshl
2[|52+zhc
(xpt_]Q!H
while(!bStop) _U.|$pU
{ /2^"c+/'p
write_nPos(); P.bxq50
Utility.sleep(500); F+o4f3N
breakWhile = true; 8;6j
"DaE(S&
OfG/7pw5%B
for(int i=0;i<nStartPos.length;i++) "s-3226kj
{ UE9RrfdN
if(!fileSplitterFetch.bDownOver) mtU{d^B
{ $%BI8_
breakWhile = false; /H4Z.|@
break; dG&^M".(
} 8[b_E5!V
} +*RaX (&
if(breakWhile) Emy=q5ryl
break; !3F3E8%
yPrF2@#XZ/
d1P|v( `S9
//count++; U$yy7}g
//if(count>4) ziDvDu=
// siteStop(); Ez8k.]qu
} LBxmozT
xXf,j#`"
[Dhqyjq
System.err.println("文件下载结束！"); zu3Fi= |0
} \sBXS.
catch(Exception e){e.printStackTrace ();} Gv[s86AP,
} SR$ 'JGfp
kmUL^vF
Brtsig,4
//获得文件长度 lZAXDxhnT
public long getFileSize() jme`Tyd
{ h1t~hrq
int nFileLength = -1; {J1iheuS}
try{ y\omJx=,
URL url = new URL(siteInfoBean.getSSiteURL()); 0G31Kou
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i;rcgd
httpConnection.setRequestProperty("User-Agent","NetFox"); PYBE?td
\TZSn1isZX
+Xp1=2Mq
int responseCode=httpConnection.getResponseCode(); Ur]/kij
if(responseCode>=400) M8Vc5
{ SRtw
processErrorCode(responseCode); HfZ^ED"}
return -2; //-2 represent access is error "OwK-
} B0U(B\~Y
PB *v45
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String sHeader; "~=-Q#xO
RL:B.Lv/W
5 w(nttYH
for(int i=1;;i++) EK= y!>
{ 06O_!"GD}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tKS[
//Utility.log(in.readLine()); C6EGM/m8
sHeader=httpConnection.getHeaderFieldKey(i); ~`Rar2%B
if(sHeader!=null) X;H\u6-|>6
{ NT0n[o^
if(sHeader.equals("Content-Length")) 8\"Gs z
{ 6I: 6+n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =[8K#PZ$w
break; y>.t[*zT
} &8w# 4*W
} O2\(:tvw
else 67hfve
break; 5RvE ),
} :_y!p
} 'da 'WZG
catch(IOException e){e.printStackTrace ();} xL1Li]fM!'
catch(Exception e){e.printStackTrace ();} =Q{?!
e@qH!.g)
]/kpEx
Utility.log(nFileLength); 5VP0Xa ~
zBlv?JwG
=/_uk{
return nFileLength; J,:&U wkv
} ,% QhS5e
zPND$3&'
}^iqhUvT F
//保存下载信息（文件指针位置） #gqh0 27
private void write_nPos() HO['o{>BL
{ ~x!up9
try{ (T0MWp0
output = new DataOutputStream(new FileOutputStream(tmpFile)); G~o!u8^;
output.writeInt(nStartPos.length); H)i|?3Ip
for(int i=0;i<nStartPos.length;i++) GkX Se)#p
{ )PTvw>
// output.writeLong(nPos); 7]xDMu'^&f
output.writeLong(fileSplitterFetch.nStartPos); _<LL@IX
output.writeLong(fileSplitterFetch.nEndPos); 6_4B!
} F'b%D
output.close(); Ac|\~w[\
} R8k4?_W?T
catch(IOException e){e.printStackTrace ();} Cp(2]Eb
catch(Exception e){e.printStackTrace ();} uyxYCc
} Hl0" zS[
;o3gR4u_L
H:]cBk^[,
//读取保存的下载信息（文件指针位置） Q0Ft.b
private void read_nPos() WN+i3hC
{ WA8<:#{e
try{ ]~I+d/k d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ztg_='n
int nCount = input.readInt(); A,9JbX
nStartPos = new long[nCount]; ^sD M>OHp
nEndPos = new long[nCount]; u1$6:"2@5k
for(int i=0;i<nStartPos.length;i++) Ctz#9[|
{ IibrZ/n6
nStartPos = input.readLong(); [|OII!"
nEndPos = input.readLong(); xKG7d8=
} &)mZ~cPU3
input.close(); t\K (zE
} Nv7-6C6<
catch(IOException e){e.printStackTrace ();} 0cq@lT6
catch(Exception e){e.printStackTrace ();} f\<r1
} N s+g9+<A
d fj23+
/RxP:>hVv
private void processErrorCode(int nErrorCode) aDKb78 1d
{ ]=00<~ l*q
System.err.println("Error Code : " + nErrorCode); $+'H000x
} :3n@].
dT|f<E/P
;7lON-@BI
//停止文件下载 ;o!p9MEpz;
public void siteStop() sgp.;h'
{ 'w+]kt-
bStop = true; '`P%;/z
for(int i=0;i<nStartPos.length;i++) B$_4ul\)
fileSplitterFetch.splitterStop(); XP@dg4Z=z
fY!?rZ)$
{Yj5Mj|#
} a{]=BY oL
} KS$t
//负责部分文件的抓取 "tz6O0D
**FileSplitterFetch.java Tn}`VW~
*/ a;HAuy`M x
package NetFox; {cm?Q\DT
%bDxvaftT
5naFnm7%
import java.io.*; %":3xj'EEI
import java.net.*; !g|O.mt
q-JTGCFl
VsQ|t/|#
public class FileSplitterFetch extends Thread { M~taZt4
~Ru\Z-q1
V.GM$
String sURL; //File URL S<i$0p8J;
long nStartPos; //File Snippet Start Position J/je/PC
long nEndPos; //File Snippet End Position FU3K?A B
int nThreadID; //Thread's ID *-T.xo
boolean bDownOver = false; //Downing is over C?zS}ob
boolean bStop = false; //Stop identical J2=4%#R!
FileAccessI fileAccessI = null; //File Access interface QL/KY G
~:a1ELqVw
<Vhd4c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O?e9wI=H
{ 2)f_L|o,m
this.sURL = sURL; 3(BL
this.nStartPos = nStart; *7!MG
this.nEndPos = nEnd; ;I>nA6A
nThreadID = id; 46:<[0Psl/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /Y0~BQC7!
} B.8B1MFm
C >*z^6Gz
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public void run() n7!T{+ge
{ 4=yzf
while(nStartPos < nEndPos && !bStop) FuHBzBoM=
{ $C[z]}iOi
)CFJXc:
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try{ [3Q0KCZ0(
URL url = new URL(sURL); KdEvu?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qezWfR`
httpConnection.setRequestProperty("User-Agent","NetFox"); ,>j3zjf^
String sProperty = "bytes="+nStartPos+"-"; t ed:]
httpConnection.setRequestProperty("RANGE",sProperty); uMcI'=
Utility.log(sProperty); 2/?Zp=|j\
iXWHI3
y3oq{Z>
InputStream input = httpConnection.getInputStream(); -nb U5o
//logResponseHead(httpConnection); u+)!C*ho
FQWjL>NB
q%3VcR$J
byte[] b = new byte[1024]; @yTu/U
int nRead; Vl5r~+$|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }i+C)VUX
{ qYoW8e
nStartPos += fileAccessI.write(b,0,nRead); ZX_QnSNZ?
//if(nThreadID == 1) \]x`f3F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DI0& _,
} 534pX7dg
UynGG@P@
0}i 9`p
Utility.log("Thread " + nThreadID + " is over!"); [<B,6nAl
bDownOver = true; eu(Fhs
//nPos = fileAccessI.write (b,0,nRead); IjhRSrCv
} ?qQ{]_q1&.
catch(Exception e){e.printStackTrace ();} Jk.x^
} UC&$8^
} JQ+Mg&&Q
r`"_D%kc
oIrc))j,$
//打印回应的头信息 HVM%B{(
public void logResponseHead(HttpURLConnection con) sX?arI=_U
{ oCo~,~kTR
for(int i=1;;i++) P}6#s'07~
{ AG >D,6Y
String header=con.getHeaderFieldKey(i); jnV#Q ;
if(header!=null) dwn|1%D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uz8eS'8
Utility.log(header+" : "+con.getHeaderField(header)); Q}&'1J
else GVT 6cR
break; !KV!Tkx h
} <@7j37,R7V
} ,IiKe_B
%Vo'\|
4H;g"nWqO
public void splitterStop() pll5m7[
{ ~Dg:siw
bStop = true; Z@q1&}D!
} B)k/]vz)*D
}ll&EB
,5 ,r.
} []OS p&
'(lsJY[-x
e,XT(KY
/* 5!Er;e
**FileAccess.java aR6~r^jB
*//文件访问(定位，写) K*~xy bA
package NetFox; Xk:x=4u&
import java.io.*; tT`S" 9T
.WglLUJ:Z
E=.J*7
public class FileAccessI implements Serializable{ 8hV4l'Pa72
i?>>%juK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %5ov!nm7
RandomAccessFile oSavedFile; r 8N<<^
long nPos; B4OFhtYE
B <Jxj
:t;\`gQoS
public FileAccessI() throws IOException KYhL}C+
{ kH06Cb
this("",0); $y)tcVc
} TbqtT_{
jp-(n z\
-6q7ze{@
public FileAccessI(String sName,long nPos) throws IOException LWo)x
{ dn5t7D^x
oSavedFile = new RandomAccessFile(sName,"rw"); RG1#\d-fE
this.nPos = nPos; *{fZA;<R
oSavedFile.seek(nPos); 6_EfOD9
} .j!:Hp(z}
AfW:'>2
a/d8_(0
public synchronized int write(byte[] b,int nStart,int nLen) |$T?P*pI.
{ p=Qo92 NH
int n = -1; Ud-c+, xX
try{ .>5E 4^$%
oSavedFile.write(b,nStart,nLen); FOa2VP%
n = nLen; \a:-xwUu<
} 6.v)q,JL
catch(IOException e) <l)I%1T_c
{ 1 RyvPP
e.printStackTrace (); q_6<}2m,U
} Xt*h2&
E-rGOm" m
r2;+ACwWf_
return n; *fDhNmQ `
} =sXk,I;
v~O2y>8Z
CIt@xi#I
} g<4@5OQKu
62OZj%CXN
H+5N+AKb@
/* :2&W9v
**SiteInfoBean.java [{-;cpM\
*/ sr$JFMTO11
package NetFox; Gy[m4n~Z5
\g;-q9g;O
6c#1Do(W+
public class SiteInfoBean { {Ve_u
9&KiG* .
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private String sSiteURL; //Site's URL :'gX//b):
private String sFilePath; //Saved File's Path >^KO5N-:4
private String sFileName; //Saved File's Name .{#J2}+[_}
private int nSplitter; //Count of Splited Downloading File &Sp2['a!
=I9RM9O<
!.5,RIf
public SiteInfoBean() 7%^/Jm
{//nSplitter的缺省值为5 G8p6p6*
//default value of nSplitter is 5 dX~$#-Ad86
this("","","",5); vZt48g
} _QOZ`st
w57D qG>
_ye74$#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z0-`D.D@\
{ r(cd?sL96R
sSiteURL= sURL; gflu!C6
sFilePath = sPath; 'e06QMp@
sFileName = sName; s8 0$
this.nSplitter = nSpiltter; EAXbbcV
La'XJ|>V
?T <2Cl'C
} gCY%@?YyN
r5g:#mF"
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public String getSSiteURL() V0!$k.Wk
{ +&h<:/ V
return sSiteURL; jLG Q^v"
} VsM~$ )
xF8^#J6>
s xp>9&
public void setSSiteURL(String value) fTg^~XmJ
{ Wc qUF"A
sSiteURL = value; (^).$g5Hg
} 0B?t:XU,
i917d@r(<
#?EmC]N7
public String getSFilePath() ^J-\s_)"
{ vhOX1'
return sFilePath; qz<>9n@o
} !O}^Y
oF0BBs$
+=N#6#1
public void setSFilePath(String value) R+y 9JE
{ ^>ICycJ
sFilePath = value; xaG( 3
} )eaEc9o>
Ri mz~}+
q71~Y:7f
public String getSFileName() qzt.k^'-^
{ qPG>0 O
return sFileName; 2j <Y>Y
} +<1MY'>y
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l" P3lKS
public void setSFileName(String value) -.=:@H}r
{ A4>j4\A[M
sFileName = value; J70r`
} V>Vu)7
ZtLZW/`
$4ZjNN@
public int getNSplitter() g/f^|:
{ -b`O"Ck*
return nSplitter; [;RO=
} lzDA0MPI:
0Mu6R=s
D@ 4sq^|2
public void setNSplitter(int nCount) ?)V?6"fFP
{ ^Ez`WP
nSplitter = nCount; L }L"BY3$
} +Cg[!6[#
} V krjs0
#m;|QWW
VSLi{=#
/* { d|lN:B
**Utility.java * ,#SwZ
*/ VteMsL/H
package NetFox; J-d>#'Wb|
/JbO$A
GA+#'R
public class Utility { fZka$ 4
cl1>S3
%s*F~E
public Utility() ^={s(B2
{ o7sIpE9
mGP&NOR0^y
6O\a\z
} o/4U`U)Q0v
=+ALh-
//线程睡眠 +Jw+rjnP
public static void sleep(int nSecond) V<ExR@|}.%
{ _Y _v&
try{ fb|%)A=
Thread.sleep(nSecond); \9N )71n(
} kxWcWl8
catch(Exception e) v4Mn@e_#c
{ >eM>Y@8=
e.printStackTrace (); < VrHWJo
} F~;UD<<"H
} :sA$LNj}
P TMJ.;
//日志 G/4~_\YMq
public static void log(String sMsg) |] cFsB#G
{ n@_aTY
System.err.println(sMsg); L=9^Y/8Q
} RGe2N|
^t}8E2mq
'y%*W:O
public static void log(int sMsg) V)jF]u~g
{ w42=tN+B
System.err.println(sMsg); OOZxs?pR
} +<rWYF(ii/
} 0x,NMS
<_3OiU=w
BFvRU5&Sz
/* Jk}Dj0o
**TestMethod.java 9CPr/q9'
*/ k] iyx
package NetFox; U0@Qc}y
$SfYO!n7Q
d7P'c!@+
public class TestMethod { ^8V8,C)
+j(7.6ia
bzyy;`;6Q~
public TestMethod() Nq"J[l*+g
{ ///xx/weblogic60b2_win.exe w=kW~gg
try{ 5bo')^xa
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0S#T}ITm4Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~nRbb;M
SiteFileFetch fileFetch = new SiteFileFetch(bean); J936o3F_
fileFetch.start(); g=e~YM85
} G'{*guYU
catch(Exception e){e.printStackTrace ();} %*];XpAE
)7 M
Xk`'m[
} zbAyYMtEk
(y5]]l
s[Whg!2~
public static void main(String[] args) #k|f%!-Vo
{ *:"p*qV*
new TestMethod(); cv"Bhql
} Y3g<%6
} 6kHuKxY,
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