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)); 1~LfR
} v*<rNZI
for(int i=0;i<nEndPos.length-1;i++) koD}o^U#
{ u!F\`Gfm_
nEndPos = nStartPos[i+1]; r_ B.bK
} C=cn.CX
nEndPos[nEndPos.length-1] = nFileLength; ]?oJxW.
} pQC|_T#u
} s| Q1;%Tj
nXI8`7D
c813NHW
//启动子线程 Q&^\YgkCf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DxpJP,wY3
for(int i=0;i<nStartPos.length;i++) Y3(I;~$!
{ {Ja(+NQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b0@K ~O;g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gwXmoM5
nStartPos,nEndPos,i); WpnP^gmX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %f1IV(3Qc
fileSplitterFetch.start(); 3Lq9pdM>2@
} ux| QGT2LY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^=1u2YdVw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -o!bO9vC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LEOa=(mN\
nEndPos = " + nFileLength); l+hOD{F4pS
// fileSplitterFetch[nPos.length-1].start(); k%kEW%I yG
'd&4MA0X
Ryxu#]s
//等待子线程结束 t imY0fx#
//int count = 0; yx:+Xy*N
//是否结束while循环 ;Bzx}7A
boolean breakWhile = false; *rHz/& ,
_9p79S<+
d"Wuu1tEY
while(!bStop) -p>1:M <
{ Q6e7Z-8
write_nPos(); A,=> |&*
Utility.sleep(500); 1\Pjz Lj
breakWhile = true; /{R.
#M+_Lk3
^3H:I8gRCl
for(int i=0;i<nStartPos.length;i++) .]JIo&>5
{ T{"Ur:p
if(!fileSplitterFetch.bDownOver) k*\)z\f
{ gFu,q`Vf*
breakWhile = false; W3\E;C-g0
break; z,2*3Be6V
} $ Y^0l
} ) jvI Nb
if(breakWhile) re}PpXRC
break; 1,Mm+_)B
&/)B d%
UL>2gl4s/
//count++; >w,jaQ
//if(count>4) M+HhTW;I=
// siteStop(); XuHR
} Wi>m}^}9
v-q-CI?B#
!cM<&3/
System.err.println("文件下载结束！"); "19#{yX4
} *FZav2]-
catch(Exception e){e.printStackTrace ();} lz36;Fp
} 8~s0%%{,M
|0}7/^
?_A[E]/H
//获得文件长度 d!Gy#<H
public long getFileSize() ]7yxXg
{ z\" .(fIV
int nFileLength = -1; ;Oqf{em];
try{ ']+!i a
URL url = new URL(siteInfoBean.getSSiteURL()); CmBgay
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >P\eHR,{-
httpConnection.setRequestProperty("User-Agent","NetFox"); 1TR+p? "
|B*B>P#
lBs-u h
int responseCode=httpConnection.getResponseCode(); ABkDOG2br
if(responseCode>=400) YZSQOLN{
{ B7|%N=S%/
processErrorCode(responseCode); <j,3Dn
return -2; //-2 represent access is error dJJq]^|
} L=EkY O%\"
,Tegrz&G
gW--[
String sHeader; >wt.)c?5
Jvsy 6R
C7*YZe
for(int i=1;;i++) W;UPA~nT~
{ !X~NL+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7iwck.*
//Utility.log(in.readLine()); ?*+U[*M
sHeader=httpConnection.getHeaderFieldKey(i); \/;c^!(<
if(sHeader!=null) J@E]Fl
{ '-Cx-=
if(sHeader.equals("Content-Length")) &ZkJ,-
{ RLF6Bc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KB :JVK^<
break; :(m, 06K
} ]y=U"g
} +_cigxpTc
else &|ne!wu
break; p5vQ.Ni*\-
} L[Z^4l_!
} ex1!7A!}g
catch(IOException e){e.printStackTrace ();} N|2d9E
catch(Exception e){e.printStackTrace ();} &oB*gGRw=7
A:GqR;;"x>
.PVYYhrt
Utility.log(nFileLength); Y9<[n)>+
+ZW>JjP*
rg k1.0U0
return nFileLength; d v[.u{#tP
} Y$n+\K
f77W{T4
L/-SWid)
//保存下载信息（文件指针位置） F1-"yX1B
private void write_nPos() 7z1@XO<D
{ LmqSxHs0Q
try{ r0lI&25w
output = new DataOutputStream(new FileOutputStream(tmpFile)); Tgtym"=xd
output.writeInt(nStartPos.length); ~K3Lbd| r
for(int i=0;i<nStartPos.length;i++) ^\Q,ACkZb
{ 2)|=+DN;
// output.writeLong(nPos); Fs $FR-x
output.writeLong(fileSplitterFetch.nStartPos); :.XlAQR~b
output.writeLong(fileSplitterFetch.nEndPos); ~,&8)1
} o4EY2
output.close(); ]w;t0Bk
} 50-7L,
catch(IOException e){e.printStackTrace ();} ?&eS}skL
catch(Exception e){e.printStackTrace ();} 0[%{YmI{W
} ||pOiR5
W$SV+q(rT
OEjX(F3=
//读取保存的下载信息（文件指针位置） #@`c7SR
private void read_nPos() wZ\93W-}
{ X;6;v]
try{ 1R~$m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6O6B8
int nCount = input.readInt(); L%5y@b{AR
nStartPos = new long[nCount]; U!o
nEndPos = new long[nCount]; .u#Hg'oP
for(int i=0;i<nStartPos.length;i++) wUr(i*
{ (UjaL@G
nStartPos = input.readLong(); yGt[Qvx#
nEndPos = input.readLong(); sGtxqnX:J
} ?;`GCE
input.close(); /]Y#*r8jRi
} v@[3R7|4
catch(IOException e){e.printStackTrace ();} i*mU<:t
catch(Exception e){e.printStackTrace ();} _[-MyUs
} 8\'tfHL
hOZTD0
$A{$$8P
private void processErrorCode(int nErrorCode) f:~G)
{ <|Lz#iV37
System.err.println("Error Code : " + nErrorCode); [u K,.G
} ,"#nJC
hf9i%,J
.txtt?ZF2
//停止文件下载 6IT6EkiT
public void siteStop() K\xM%O?
{ XBCHJj]k
bStop = true; T$2A2gb`
for(int i=0;i<nStartPos.length;i++) y< dBF[
fileSplitterFetch.splitterStop(); ~< UYJc
tg#jjXV\0p
dazML|1ow
} 6*S/frE
} NR_3nt^h
//负责部分文件的抓取 qtZzJ>Y
**FileSplitterFetch.java 86-Rm
*/ AU`z.Isf
package NetFox; yQj J-g(.
af>i
Z'k?lkB2i
import java.io.*; 2'M5+[8y8
import java.net.*; ]3*w3Y!XK
vW*Mf}=
,=Wj*S)~
public class FileSplitterFetch extends Thread { H'YKj'
%_Lz0L64k
z$%8'
String sURL; //File URL FN!?o:|(
long nStartPos; //File Snippet Start Position *lLCH,
long nEndPos; //File Snippet End Position URm<Ji
int nThreadID; //Thread's ID zFO0l).
boolean bDownOver = false; //Downing is over MDIPoS3BRa
boolean bStop = false; //Stop identical <HRPloVKo
FileAccessI fileAccessI = null; //File Access interface ,{q#U3
I$+=Fb'N0
O ] !tK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DU"Gz!X]Jd
{ p2b~k[
this.sURL = sURL; <#M1I!R
this.nStartPos = nStart; 6<S-o|Xw
this.nEndPos = nEnd; [T7&)p
nThreadID = id; x<!]#**;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [&&#~gz
} 2@Nd02v|
~$4(|Fq/
UYZC% $5x
public void run() P(8Yz W
{ vS5}OV
while(nStartPos < nEndPos && !bStop) 6vNn;-gg.
{ %4x0^<k~
_$IWr)8f
zB+e;x f|
try{ )3e_Hs+
URL url = new URL(sURL); oupWzjo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;rL1[qwk
httpConnection.setRequestProperty("User-Agent","NetFox"); ceks~[rP
String sProperty = "bytes="+nStartPos+"-"; Z P|k3
httpConnection.setRequestProperty("RANGE",sProperty); ]Ri=*KZa
Utility.log(sProperty); BRu}"29
H'!OEZ
'*Dp2Y{7
InputStream input = httpConnection.getInputStream(); p{GO-gE@
//logResponseHead(httpConnection); _UkBOJ:G$H
[>p!*%m
( EJ1g^|"
byte[] b = new byte[1024]; x@oxIXN
int nRead; [Nm?qY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r 56~s5A
{ kkHK~(>G
nStartPos += fileAccessI.write(b,0,nRead); KV;q}EyG
//if(nThreadID == 1) .0U[nt6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OzC%6;6h
} 85|u;Fxf
b}Im>n!
1qn/*9W}=
Utility.log("Thread " + nThreadID + " is over!"); X.#9[3U+
bDownOver = true; FPK=Tr:b
//nPos = fileAccessI.write (b,0,nRead); F)eP55C6
} V[WZ#u-p
catch(Exception e){e.printStackTrace ();} 0k\,z(e
} kP('X/
} M+ <SSi"
^5~x*=_
.e3@fq
//打印回应的头信息 q$v0sTk0Y
public void logResponseHead(HttpURLConnection con) .,S`VNU
{ k-^^Ao*@
for(int i=1;;i++) NF |[j=?
{ 4,QA {v
String header=con.getHeaderFieldKey(i); yCkc3s|DA;
if(header!=null) -9+$z|K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a $'U?%
Utility.log(header+" : "+con.getHeaderField(header)); p8.JJt^
else 525^/d6v
break; N|)e {|k
} N&k\X]U
} n'pJl
jYAm}_?No
ZWuNl!l>
public void splitterStop() INk|NEX
{ Snmv
bStop = true; 3My}u>
} yNwSiZE X
j8?! J^TC
h1 "#
} oIj/V|ByK
-3d`e2^&}
:si&A;k
/* ^oq|^O
**FileAccess.java L?8OWLjRy
*//文件访问(定位，写) DTi^* Wj
package NetFox; vYLspZ;S
import java.io.*; w0sy@OF
9'|k@i:
n?q+:P
public class FileAccessI implements Serializable{ s`,g4ce`
{s6#h#U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rWO#h{
RandomAccessFile oSavedFile; zU0JwZi
long nPos; 86qQ"=v
dn42'(p@G
$'!n4}$}
public FileAccessI() throws IOException a.O"I3{?h
{ (<OmYnm
this("",0); T51oNO%^
} q]!FFi{w;
&DtI+)[|
6y`FW[
public FileAccessI(String sName,long nPos) throws IOException dR,a0+!
{ K!>3`[:I"
oSavedFile = new RandomAccessFile(sName,"rw"); }7fzEo`g
this.nPos = nPos; b/#<::D `
oSavedFile.seek(nPos); ib]<;t
} L4u.cHJ}0
-s0J8b
/ )[\+Nc
public synchronized int write(byte[] b,int nStart,int nLen) @LU[po1I
{ e2nZwPH
int n = -1; ? )IH#kL
try{ vu*{+YpH
oSavedFile.write(b,nStart,nLen); Q3t%JP>;g
n = nLen; =''*'a-P
} Y<@_d
catch(IOException e) l:#'i`;
{ slr>6o%W`
e.printStackTrace (); U&$I!80.
} <A\g*ld
P6v@ Sn
s1%2({wP
return n; [P)](8nR[
} 5*B'e{C
mkBQTQGT
.rDao]K
} 8|hi2Qeu,c
"4*QA0As
&s\,+d0
/* ^b.fci{1m
**SiteInfoBean.java <X97W\
*/ +@@( C9
package NetFox; iN@|08
<P Vmr2Jp"
q}g0-Da
public class SiteInfoBean { VF7H0XR/k5
wmP[\^c%$j
3] U/^f3
private String sSiteURL; //Site's URL aH500
private String sFilePath; //Saved File's Path LzB*d
private String sFileName; //Saved File's Name jM'Fb.>~
private int nSplitter; //Count of Splited Downloading File D2:ShyYAS
%a-fxV[
r"5\\qf5*
public SiteInfoBean() RC/&dB
{//nSplitter的缺省值为5 +fMW B
//default value of nSplitter is 5 yN#]Q}4
this("","","",5); , d4i0;2}+
} !E *IktAI
r9-)+R J
`E>o:tff
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cf_X=;yaqy
{ qNkX:|j
sSiteURL= sURL; yW_goS0
sFilePath = sPath; M|$A)D1
sFileName = sName; D@iS#+22
this.nSplitter = nSpiltter; b0/[+OY
=D 5!Xq'|
Zk gj_
} 2+LvlS)C
U4e9[=q`'
z-S8s2.Fd
public String getSSiteURL() `3UvKqe
{ v[m1R'
return sSiteURL; xz/G$7q7
} mj2sbRiSR=
ck`$ `
q1%xk=8
public void setSSiteURL(String value) u,@x7a,z
{ X=JAyxY
sSiteURL = value; KH[Oqd
} J8`vk#5
V}G;oz&>)
.ityudT<
public String getSFilePath() &gvX<X4e
{ mgEZiAV?
return sFilePath; =Ajw(I[56
} Cz4l
M""X_~&I"
OgyHX>}bH
public void setSFilePath(String value) D_I_=0qNd
{ 8GT{vW9
sFilePath = value; jATN):8W
} 4+0:(=>[%
B|BJkY'
& =vi]z:[
public String getSFileName() z#olKBs
{ DTx>^<Tk
return sFileName; O@KAh5EB
} A Rjox`
IAbH_+7O
FBI^}^#_
public void setSFileName(String value) a^9}ceu?
{ &R}2/Mt
sFileName = value; Z9PG7h
} ]<E\J+5K
k5GJrK+
`"E<%$|ZQy
public int getNSplitter() xTdh/}
{ ZCkwK
return nSplitter; MqswYK-s
} Y<`uq'V
Yg")/*!H
gMZ `
public void setNSplitter(int nCount) [Q20c<,
{ 2ISnWzq;
nSplitter = nCount; locf6%2g~
} e%&/K7I"?
} qznd'^[
?$X1X`@
6imQjtI
/* e_CgZ
**Utility.java y+a]?`2
*/ ;jpsH?3g
package NetFox; .AHww7
T$9tO{
x-s]3'!L
public class Utility { Y-:{a1/RKo
ucC'SS
Ps7Bt(/
public Utility() t{ScK%S6
{ ]1n =O"vE
mE_?E&T`|
rM(2RI4O`0
} -*C+z!?BP
i!EN/Bd
//线程睡眠 x AR9* <-
public static void sleep(int nSecond) '|l1-yD_
{ 4P}<86xk
try{ #a"gW,/K
Thread.sleep(nSecond); IG~d7rh"
} XQL]I$?
catch(Exception e) Q68q76
{ !XS ;&s7[*
e.printStackTrace (); go$zi5{h#
} SdBo sB3v>
} Q+'QJ7fw'|
,v+~vXO&\
//日志 JN-wToOF
public static void log(String sMsg) E h>qUa
{ k9?fE
System.err.println(sMsg); D>Dch0{H,:
} 1-60gI1)
8!{F6DG
$17utJ58
public static void log(int sMsg) J(\f(jh/
{ elf2!
System.err.println(sMsg); F&x9.
} %B'*eBj~fw
} -5t.1/
DkGC+Dw
!Wz%Hy:ZK
/* [1{uK&$e
**TestMethod.java ^X/[x]UOT@
*/ E)w^odwMU
package NetFox; INj2B@_
*XZlnO
4r'f/s8"#
public class TestMethod { Dy_Za.N2
y0D="2)
k&PxhDf
public TestMethod() qXJBLIG
{ ///xx/weblogic60b2_win.exe &}G2;O}3
try{ )a%kAUNj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2pEr s|r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wp<4F6C$@
SiteFileFetch fileFetch = new SiteFileFetch(bean); gIfl}Jat
fileFetch.start(); "eiZZSz
} %;|^*?!J0
catch(Exception e){e.printStackTrace ();} B&E qd
h{&}p-X&[
qZ6Mk9@M
} MjW g
8QN#PaY
=)GhrWeVi4
public static void main(String[] args) m:,S1V_jl
{ t Tky
new TestMethod(); ErNL^Se1
} |i7j}i
} b xT|
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