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)); qY]IX9'kV
} cxFfAk\,en
for(int i=0;i<nEndPos.length-1;i++) cfyN)#9
{ M;ac U~J
nEndPos = nStartPos[i+1]; *`>(K&
} U<|kA(5
nEndPos[nEndPos.length-1] = nFileLength; r5xu#%hgp;
} L5Rj;qhi
} j)?I]j/
iqig~fjK~
U{gJn#e/.
//启动子线程 ]7}2"?J4v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eNY$N_P
for(int i=0;i<nStartPos.length;i++) 0.4c|-n
{ &Y;z[+(P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6Daz1Pxd+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -z)I;R
nStartPos,nEndPos,i); !n~p?joJ*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'KMyaEh.u
fileSplitterFetch.start(); -)(HG)3
} \/I@&$"F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /Li?;H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u~=>$oT't
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,~`R{,N`
nEndPos = " + nFileLength); qd6XKl\5
// fileSplitterFetch[nPos.length-1].start(); '9>z4G*Td
xV @X%E
{wiw]@c8
//等待子线程结束 f'Dl*d
//int count = 0; v?F~fRH
//是否结束while循环 6H\3
boolean breakWhile = false; .-T^S"`d|
LSv0zAIe/
j yR9a!
while(!bStop) Jb Hn/$
{ 8q{ %n
write_nPos(); glbU\K> >
Utility.sleep(500); g|tnYN
breakWhile = true; nKC$ KC
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YIGQDj@
for(int i=0;i<nStartPos.length;i++) Rb\M63q
{ h1} x2
if(!fileSplitterFetch.bDownOver) >y#<WB$i
{ T B~C4HK=
breakWhile = false; ; 6Js
break; ~]a:9Ev*
} |f;u5r!^=
} Xs$k6C3
if(breakWhile) ]f=108|8
break; P#-Ye<V~J(
d#cw`h<c~
a^t#kdT
//count++; 2uu"0Rm%
//if(count>4) %:yJ/&-Q,Z
// siteStop(); (Vnv"= (
} :KGUO{_u
V6)\;c
avrf]raM|
System.err.println("文件下载结束！"); 7'\<\oT
} g+|1khS)
catch(Exception e){e.printStackTrace ();} fl*]ua
} 7'uuc]\5>
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RI9&KS
//获得文件长度 ;2y3i5^k
public long getFileSize() 7KXc9:p+
{ >xb}AY;
int nFileLength = -1; m?VA 1
try{ c,-3+b
URL url = new URL(siteInfoBean.getSSiteURL()); oMk6ZzZ,>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cL}}^
httpConnection.setRequestProperty("User-Agent","NetFox"); $x#0m
ZE863M@.
T+7-6y+ d
int responseCode=httpConnection.getResponseCode(); 4Ynv=G Qz
if(responseCode>=400) `3m7b!0k
{ J24<X9b
processErrorCode(responseCode); aEBQx
return -2; //-2 represent access is error -}Vnr\f
} 4/e|N#1`;[
MgkeD
qT}<D`\
String sHeader; #lXwBfBMf
:23w[vt=
".Z|zt6C
for(int i=1;;i++) aGY R:jR$
{ ( `T;nz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #m[R1G#
//Utility.log(in.readLine()); s>hNwb/
sHeader=httpConnection.getHeaderFieldKey(i); PoTJ4z
if(sHeader!=null) 6wK>SW)#&j
{ g93-2k,
if(sHeader.equals("Content-Length")) L,6v!9@
{ eK[8$1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `5,46_
break; I~ Q2jg2
} r&6X|2@
} C.`C T7
else FJxg9!%d
break; NbnahhS
} LCKCg[D
} 1$nlRQi
catch(IOException e){e.printStackTrace ();} 4+Aht]$hC
catch(Exception e){e.printStackTrace ();} ehehTP
~5S[Sl
03Czx`
Utility.log(nFileLength); eU/o I}A
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eW%Cef
return nFileLength; J?9K|4 )
} g:&YSjO>G
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,=!_7'm
//保存下载信息（文件指针位置） KWwEK]
private void write_nPos() }t5-%&gBY0
{ ?}p~8{ '
try{ %@Mv-A6)
output = new DataOutputStream(new FileOutputStream(tmpFile)); v;_m1UpuW
output.writeInt(nStartPos.length); `wIMu$i
for(int i=0;i<nStartPos.length;i++) W%Jw\ z=
{ ]34fG3D|
// output.writeLong(nPos); kF{'?R5w
output.writeLong(fileSplitterFetch.nStartPos); ^\o3V<
output.writeLong(fileSplitterFetch.nEndPos); ppL*#/jYt
} %a\!|/;6
output.close(); k2]fUP
} va6e]p*Oy
catch(IOException e){e.printStackTrace ();} YO&=fd*
catch(Exception e){e.printStackTrace ();} i3 ?cL4
} n[|*[II
K,B qVu
i{T mn
//读取保存的下载信息（文件指针位置） \0bao<
private void read_nPos() I$yFCdXr
{ LTsX{z
try{ EL/~c*a/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C=k]g
int nCount = input.readInt(); s0EF{2<F
nStartPos = new long[nCount]; OGA_3|[S
nEndPos = new long[nCount]; @-B)a Z
for(int i=0;i<nStartPos.length;i++) al#BfcZW
{ =17d7#-
nStartPos = input.readLong(); R9+0ZoS
nEndPos = input.readLong(); K+WbxovXU
} w8(8n&5
input.close(); jg)+]r/hS
} 3:H[S_q
catch(IOException e){e.printStackTrace ();} Mk=M)d`
catch(Exception e){e.printStackTrace ();} r1pj-
} {Sl#z}@s
w^BF.Nu
ML:Zm~A1U
private void processErrorCode(int nErrorCode) $G UCVxs
{ Z|t`}lK
System.err.println("Error Code : " + nErrorCode); D^m`&asC
} .{\lbI
oh^/)2W
ORCG(N
//停止文件下载 3haR/YN
public void siteStop() C0O$iWs=
{ )s-[d_g
bStop = true; %?sPKOh3N}
for(int i=0;i<nStartPos.length;i++) q7#4e?1
fileSplitterFetch.splitterStop(); g]$e-X@k
P0 4Q_A
|XGj97#M
} S1vUP5cZ
} -e2f8PV?3
//负责部分文件的抓取 5I`_SOa!
**FileSplitterFetch.java Yo-$Z-ud
*/ PH1jN?OEwZ
package NetFox; ]?un'$%e
>IT19(J;A
UR{OrNg*
import java.io.*; s@$SM,tnn
import java.net.*; 6x*$/1'M3;
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D*_Z"q_B
public class FileSplitterFetch extends Thread { uge~*S
r*F^8_YMK
+sY8<y@%
String sURL; //File URL 6d;_}
long nStartPos; //File Snippet Start Position 4{v?<x8
long nEndPos; //File Snippet End Position 6?`3zdOeO
int nThreadID; //Thread's ID O-3R#sZ0
boolean bDownOver = false; //Downing is over )i^+=TZq
boolean bStop = false; //Stop identical Jc=~BT_G
FileAccessI fileAccessI = null; //File Access interface eV5 e:9
v?@=WG
t3l-]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S!Bnz(z
{ lWyg_YO@
this.sURL = sURL; n1Z*wMwC
this.nStartPos = nStart; 8V?*Bz-4`
this.nEndPos = nEnd; H~1o^ gU
nThreadID = id; &Hj1jM'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oF(=@UL
} j6&q6C X
F?c: ).g
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public void run() w3>.d(Q
{ O>c2*9PM
while(nStartPos < nEndPos && !bStop) SB)Hz8<
{ N5F+h94z]
A+QOox]<
b/]@G05>>
try{ .-mlV ^
URL url = new URL(sURL); 9Od|R"aS|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^ZD0rp(l
httpConnection.setRequestProperty("User-Agent","NetFox"); 3?x}48
String sProperty = "bytes="+nStartPos+"-"; $5r1Si)
httpConnection.setRequestProperty("RANGE",sProperty); D/`b~Yl
Utility.log(sProperty); &0Bs?oq_
4_KRH1
JTS<n4<a
InputStream input = httpConnection.getInputStream(); 5T-CAkR{n
//logResponseHead(httpConnection); 8b|m66#|
s~b!3l`gu
@|;XDO`k;
byte[] b = new byte[1024]; yyv<MSU8
int nRead; '{F Od_uk%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VthM`~3
{ 8eDKN9kq
nStartPos += fileAccessI.write(b,0,nRead); d-ML[^G
//if(nThreadID == 1) Fu*Qci1Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KkPr08
} /zTx+U.\I
,AuejMd
/8[T2Z!
Utility.log("Thread " + nThreadID + " is over!"); xN>+!&3%w
bDownOver = true; |Qz"Z<sNYw
//nPos = fileAccessI.write (b,0,nRead); ~|R/w%*C
} |QO)xEn~
catch(Exception e){e.printStackTrace ();} r34 GO1d
} pP^"p"<s
} KKGwMJku}
JrJTIUf_
mKZ^FgG
//打印回应的头信息 2O+fjs
public void logResponseHead(HttpURLConnection con) Y}hz UKJ
{ hB1Gtc4n
for(int i=1;;i++) I`KBj6n
{ ,&aD U
String header=con.getHeaderFieldKey(i); VCCG_K9'
if(header!=null) yiAusl;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Zoyo:vv&
Utility.log(header+" : "+con.getHeaderField(header)); jx-8%dxtZ
else &Tn7
break; 40Z/;,wp{
} - *_"ZgE
} /e50&]2w
Jo9!:2?
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public void splitterStop() 3=Va0}#&
{ 7p+uHm
bStop = true; 5imqZw
} ghVxcK
,}HnS)+
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} E?^A+)<"
nk+*M9r|I
xyaU!E*
/* SO}en[()O
**FileAccess.java m9li%p
*//文件访问(定位，写) 5:x .<
package NetFox; #7dM %
import java.io.*; JrVBd hLr
fH[:S9@
tX.{+yyU
public class FileAccessI implements Serializable{ 3I.0uLjg^
i \u"+:j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^`Qh*:T$
RandomAccessFile oSavedFile; &xjeZh4-
long nPos; u9^R ?y
_.ELN/$-
$jKeJn8,
public FileAccessI() throws IOException jHWJpm(
{ lL6qK&;
this("",0); J"O#w BM9
} j,CMcP7A -
Mb[4G>-v=
n:5*Tg9
public FileAccessI(String sName,long nPos) throws IOException zV=(e( [
{ h| +(
oSavedFile = new RandomAccessFile(sName,"rw"); dL!K''24{
this.nPos = nPos; p!w}hB598
oSavedFile.seek(nPos); k.CHMl]
} > [|SF%
ky5gU[
| QI-gw
public synchronized int write(byte[] b,int nStart,int nLen) 2\1\Jn#q
{ j])nkm7_
int n = -1; iWNTI
try{ )QiHe}
oSavedFile.write(b,nStart,nLen); >5!/&D.q
n = nLen; J"dp?i
} ALY% h!L
catch(IOException e) vXi}B
{ ds9`AiCW>
e.printStackTrace (); *cn#W]AE
} 3((53@s98
Y)X58_En
K\GIh8L
return n; 5"JnJH
} xuDn:
e`Z3{H}
YJ{d\j
} wOp# mT
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SY}iU@xo
/* n!(g<"
**SiteInfoBean.java Q,A`"e#:
*/ iAlFgOk'
package NetFox; V6ioQx=K#
NR)[,b\v
CQcb !T
public class SiteInfoBean { "rA:;ntz
fJ3qL#'
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private String sSiteURL; //Site's URL ;Q.g[[J/p
private String sFilePath; //Saved File's Path {@u}-6:wAT
private String sFileName; //Saved File's Name m 5NF)eL
private int nSplitter; //Count of Splited Downloading File ;,h*s,i
IBzHXa>75
ptmPO4f
public SiteInfoBean() Ueyt}44.e2
{//nSplitter的缺省值为5 Q nqU!6k@
//default value of nSplitter is 5 +C)auzY7N
this("","","",5); =`X;fz
} )LYj,do
ab 1\nzpd
&xqe8!FeA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) : |c,.uO
{ :l>T~&/98
sSiteURL= sURL; cF[[_
sFilePath = sPath; B|O/h!H.
sFileName = sName; qt}[M|Q^r
this.nSplitter = nSpiltter; yf=ek==
9e Dji,
>P=xzg79
} TJB0O]@3
'Sc3~lm(dH
GfQP@R"
public String getSSiteURL() /j'We-C
{ ZtEHP`Iin
return sSiteURL; HC8{);
} V_(?mC
Iq\sf-1E
XY|-qd}A
public void setSSiteURL(String value) =k[!p'~jD
{ 3RRZVc* ^
sSiteURL = value; ,U'Er#U
} 'U)~|(\i
Z3R..vy8
?#kI9n<O
public String getSFilePath() -c=IO(B/
{ T[XI
return sFilePath; 5.|rzk>
} _TB\@)\
m`9)DsR N
%'* |N[
public void setSFilePath(String value) YS{
{ ,oP-:q!PC
sFilePath = value; 2+GF:[$
} 3a{QkVeV7
hP,1;`[1
,h]N*Z-I"
public String getSFileName() :7Vm]xd}do
{ 4:<0i0)5
return sFileName; 9~,eu
} oUw-l_M]
z6G^BaT'
~|J6M
public void setSFileName(String value) uB,B%XHj
{ !4jS=Lhe>
sFileName = value; oqDW}>.
} %e%nsj6
JZL!(>tI
q{7s.m >
public int getNSplitter() xel&8 `
{ ~.x!st}
return nSplitter; @-b}iP<T
} H[,.nH_>+
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public void setNSplitter(int nCount) [1nI%/</>
{ fJE ki>1
nSplitter = nCount; V7401@F
} \\)-[4uC
} 5Ll[vBW
Gs?W7}<$
9$DVG/
/* Zc9 n0t[
**Utility.java "-xC59,
*/ :{66WSa@Dd
package NetFox; o3WkbMJWM
Z^fF^3x
~hvhT}lE
public class Utility { :za!!^
{J0^S
!)9zH
public Utility() L8j,?u#
{ +&?VA!}.
iD(K*[;lc
#Y18z5vo
} z|b4w7I
&6\rKOsn
//线程睡眠 @6D<D6`
public static void sleep(int nSecond) 9i`LOl:;
{ tIr66'8
try{ d,QJf\fc"
Thread.sleep(nSecond); VS).!;>z
} XPEjMm'*b3
catch(Exception e) akqXh 9g
{ `a6;*ry
e.printStackTrace (); tcX7Ua(I`
} 95!xTf
} Pdn.c1[-a
v;$^1I
//日志 nlmkkTHF8
public static void log(String sMsg) I'@ }Yjm|
{ @s IZ
System.err.println(sMsg); *Cb(4h-
} S&=B&23T
!X.N$0
by06!-P0[
public static void log(int sMsg) _&z>Id`w
{ sJ?kp^!g
System.err.println(sMsg); 7CIje=u.q
} Zwt!nh
} 8%|x)
'QV4=h`
~0}eNz*
/* 'qM3.U
**TestMethod.java q(r2\
*/ p5H Mg\hT
package NetFox; *"4<&F S
Rxli;blzi
x9ws@=[:
public class TestMethod { 0?:ZERv
]t=>#
u3ZG;ykM
public TestMethod() Fu`g)#Z
{ ///xx/weblogic60b2_win.exe I&xRK'
try{ Q.|2/6hD7[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {'ZnxK'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;I7Z*'5!
SiteFileFetch fileFetch = new SiteFileFetch(bean); GS,pl9#V_
fileFetch.start(); vn_avYwiy
} @!MbPS
catch(Exception e){e.printStackTrace ();} foFn`?LF
aH$~':[93
:qZ^<3+:
} drZw#b
@fK`l@K
9BY b{<0tS
public static void main(String[] args) UB1/FM4~
{ W#wM PsB
new TestMethod(); "Dk:r/
} Ww p^dx`!
} <Q0&[q;Z
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