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)); U@n5:d=
} z\8s |!
for(int i=0;i<nEndPos.length-1;i++) 8JF<SQ
{ >BK/HuS
nEndPos = nStartPos[i+1]; kw gLK@@%1
} BYhiP/^
nEndPos[nEndPos.length-1] = nFileLength; x^pt^KR;
} N'aq4okoL
} ]vs}-go
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"%a<+D
//启动子线程 %, iAngF'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5/h-Hr
for(int i=0;i<nStartPos.length;i++) T{`VUS/
{ r%ebC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OW@)6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FeO1%#2<y
nStartPos,nEndPos,i); 5jwv!L<n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bqA`oRb\
fileSplitterFetch.start(); VmQ'
} mTUoFXX[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &=n/h5e0t&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %xQ'i4`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2e-bt@0t
nEndPos = " + nFileLength); RjO0*$>h
// fileSplitterFetch[nPos.length-1].start(); !7)#aXt&
}BL7P-km
cZ)mp`^n7
//等待子线程结束 &nI>`Q'
//int count = 0; PeqW+Q.
//是否结束while循环 3tJfh=r=1
boolean breakWhile = false; q+p}U}L= k
Gr/}&+S
S ~fz
while(!bStop) =2=rPZw9
{ "$o>_+U
write_nPos(); g)TZ/,NQ{
Utility.sleep(500); -OU{99$aS
breakWhile = true; o,c}L9nvt
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'kY/=*=Q
for(int i=0;i<nStartPos.length;i++) |>'N^
{ Meep
if(!fileSplitterFetch.bDownOver) |K{d5\_
{ c?. i;4yh
breakWhile = false; 5~jz| T}s
break; U] GD6q
} "M /Cl|z
} n=F rv*"Z
if(breakWhile) oaPWeM+
break; 5G(dvM-n
HQ7g0:-^a>
|mHf7gCX
//count++; l:JVt`A4?
//if(count>4) ;fW~Gb?"
// siteStop(); FBB<1({A
} G}+@C]
\f(zMP
E"S#d&9
System.err.println("文件下载结束！"); ` V [4
} C,$o+q*)W9
catch(Exception e){e.printStackTrace ();} w%iwxo
} 2@ 9?~?r
+lVA$]d
'xG J;pY
//获得文件长度 o 7tUv"Rs
public long getFileSize() <rK[&JlJ
{ 4'*.3f'bp
int nFileLength = -1; 2PRiiL@
try{ +L.D3
URL url = new URL(siteInfoBean.getSSiteURL()); Qox/abC h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V]+y*b.60
httpConnection.setRequestProperty("User-Agent","NetFox"); Y~{<Hs
y {Bajil
+PADy8
int responseCode=httpConnection.getResponseCode(); %Y=r5'6l
if(responseCode>=400) \~+b&
{ 8OV=;aM?{
processErrorCode(responseCode); vWM&4|Q1~
return -2; //-2 represent access is error 0,0Z!-Y
} 'Q:%s
A[7H-1-
-C~zvP;a
String sHeader; kp<Au)u
2YY4 XHQS
qpCaW0]7
for(int i=1;;i++) aQ\SV0PI
{ h%W,O,K/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oQmXKV+[v
//Utility.log(in.readLine()); r nr-wUW@
sHeader=httpConnection.getHeaderFieldKey(i); mTWd+mx
if(sHeader!=null) T8|?mVv s
{ #5{xWMp/0
if(sHeader.equals("Content-Length")) %W7%]Z@j
{ \zFCph4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c*E7nc)u
break; 0|j44e}
} G"-V6CA[
} MD<x{7O12>
else nw`rH*
break; Y,}h{*9Kd
} cNmAr8^}
} R13k2jLSQ
catch(IOException e){e.printStackTrace ();} JeNX5bXW
catch(Exception e){e.printStackTrace ();} /}6y\3h
wL3RcXW``e
V?"U)Y@Y
Utility.log(nFileLength); f"*4R kG
(GL'm[V
SG\ /m'F
return nFileLength; C R?}*
} YLA(hg|
s[h;9 I1w
ftPhE)i
//保存下载信息（文件指针位置） \ctzv``/n
private void write_nPos() $!9/s S?
{ XXA'B{@Y)
try{ aZ\Z7(
output = new DataOutputStream(new FileOutputStream(tmpFile)); p"~@q}3
output.writeInt(nStartPos.length); Vq`/]&
for(int i=0;i<nStartPos.length;i++) +2 oZML
{ cl&?'` )
// output.writeLong(nPos); ~uZ9%UB_m
output.writeLong(fileSplitterFetch.nStartPos); _xi&%F/
output.writeLong(fileSplitterFetch.nEndPos); j#P4&
} OAW_c.)5D
output.close(); oPaoQbR(A
} vf<Dqy<M.
catch(IOException e){e.printStackTrace ();} rKslgZhQ
catch(Exception e){e.printStackTrace ();} hrzxc4,W
} >yT1oD0+x
^q/^.Gf
,P`GIGvkA
//读取保存的下载信息（文件指针位置） ^b|? ?9&
private void read_nPos() +MaEet
{ GeB&S!F
try{ .-& =\}^2l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Et-|[ eL
int nCount = input.readInt(); ps,Kj3^T<
nStartPos = new long[nCount]; zZRLFfz<9
nEndPos = new long[nCount]; tB`"gC~
for(int i=0;i<nStartPos.length;i++) Viw,YkC
{ <b_K*]Z
nStartPos = input.readLong(); 2~g-k3
nEndPos = input.readLong(); F-ofR]|)>
} 4f8XO"k7t=
input.close(); y $uq`FW
} b`S9#`
catch(IOException e){e.printStackTrace ();} iWr #H
catch(Exception e){e.printStackTrace ();} /c-k{5mH%
} L?0IUGY
+`Nu0y!rj
<[}zw!z
private void processErrorCode(int nErrorCode) yY49JZ
{ h;r^9g
System.err.println("Error Code : " + nErrorCode); G,Eh8HboK
} &Fuk+Cu{
Zj ` ;IYFG
5MCgmF*Y2
//停止文件下载 <_eEpG}9
public void siteStop() LCA+y1LP-_
{ ]|w~{X!b4
bStop = true; p=x&X~
for(int i=0;i<nStartPos.length;i++) !J<0.nO/:
fileSplitterFetch.splitterStop(); 4[;}/-
b 1Wz
[] "bn9 +
} )t-P o'RW
} _1$Y\Y
//负责部分文件的抓取 yW7>5r
**FileSplitterFetch.java rZ-< Ryg
*/ 1)ij*L8k
package NetFox; tlvZy+Blv
E2cZk6~m{
ZK'WKC
import java.io.*; 4s_5>r4
import java.net.*; 0~WXA=XG
[U^Cz{G
g;AW
public class FileSplitterFetch extends Thread { d*k5h<jM
Rb:?%\=
2MYez>D
String sURL; //File URL saQ ~v@
long nStartPos; //File Snippet Start Position ks%;_~b
long nEndPos; //File Snippet End Position p^ROt'eQ<
int nThreadID; //Thread's ID !~'D;Jh
boolean bDownOver = false; //Downing is over k6z]"[yu
boolean bStop = false; //Stop identical 7MJ\*+T|03
FileAccessI fileAccessI = null; //File Access interface \/Q~C!
M($GZ~ b%A
v6uRzFw
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HEa7!h[a'
{ zYdieE\-
this.sURL = sURL; &%/T4$'+Y+
this.nStartPos = nStart; Q\xDAOEL
this.nEndPos = nEnd; ?LU>2!jN
nThreadID = id; V7gL*,3>=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UEYJd&n0CB
} C;U4`0=8
3syA$0TZt
KXcRm)
public void run() f qWme:x
{ FoZI0p?L)9
while(nStartPos < nEndPos && !bStop) l>s@&%;Mg
{ 4u41M,nJQd
I|;zGmg#k
".( G,TW
try{ &><b/,]
URL url = new URL(sURL); upeioC q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?GLCd7TP
httpConnection.setRequestProperty("User-Agent","NetFox"); ph!h8@e
String sProperty = "bytes="+nStartPos+"-"; mO]dP;,
httpConnection.setRequestProperty("RANGE",sProperty); 5K$<Ad4$b
Utility.log(sProperty); ).e}.Z6[i`
yqtHlz%
H)dZ0n4T
InputStream input = httpConnection.getInputStream(); xkSVD6Km
//logResponseHead(httpConnection); e8(Qx3T?b
j*f\Z!EeZ
6jm/y@|F!
byte[] b = new byte[1024]; u%"5<ll
int nRead; rqm":N8@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -w)v38iX!
{ /f+BeQ3#/
nStartPos += fileAccessI.write(b,0,nRead); tk8\,!9Q
//if(nThreadID == 1) L@Qvj-5e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .i|nn[H &
} <~_XT>`y
z_{_wAuY
e?O$`lf
Utility.log("Thread " + nThreadID + " is over!"); %i?v)EW
bDownOver = true; -3b_}by
//nPos = fileAccessI.write (b,0,nRead); j:2F97
} >/%XP_q%`e
catch(Exception e){e.printStackTrace ();} -GB,g=Dk
} i;|I;5tC
} a gL@A
\ZE=WvnhZ
DeT$4c*:[
//打印回应的头信息 ,TB$D]u8
public void logResponseHead(HttpURLConnection con) M&9urOa`
{ Au(oKs<
for(int i=1;;i++) wPcEvGBN=
{ cb{"1z
String header=con.getHeaderFieldKey(i); \,v+ejhw
if(header!=null) 2<w vO 9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %AWc`D
Utility.log(header+" : "+con.getHeaderField(header)); mZM7 4!4X
else ,69547#o
break; ;$4&Qp:#
} "*MF=VB1
} vO/3bu}
Vu E$-)&)
HN5,MD[
public void splitterStop() qFq$a9w|@
{ WoNY8 8hT
bStop = true; ]-SJ";aU
} "o_'q@.}
6'<[QoW];
G!%8DX5
} J^<uo(
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&rX#A@=
/* C[#C/@
**FileAccess.java dq'f >Sz}
*//文件访问(定位，写) ;mwnAO
package NetFox; %p&y/^=0I
import java.io.*; zf^|H% ~^
Unb3 Gv#O
K"X"2c1o
public class FileAccessI implements Serializable{ M,bs`amz
vEGI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =]"I0G-s!
RandomAccessFile oSavedFile; |z:4T%ES
long nPos; {c*5 )x!
CHD.b%_|
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public FileAccessI() throws IOException T"gk^.
{ a1_o
this("",0); 6Q_A-X3hk
} ev_'.t'
Q[|*P ] w
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public FileAccessI(String sName,long nPos) throws IOException $p$p C/:%
{ iJmzVR+
oSavedFile = new RandomAccessFile(sName,"rw"); fz2}M:u
this.nPos = nPos; E\;%,19Ob
oSavedFile.seek(nPos); &%t&[Se_~
} '!,(G3
1v,R<1)&
y%kZ##
public synchronized int write(byte[] b,int nStart,int nLen) u3pFH(
{ %NC/zqPH~
int n = -1; LGX+_"
try{ e6jA4X+a
oSavedFile.write(b,nStart,nLen); |(PS bu
n = nLen; ,_,*I/o>B
} (hQi {
catch(IOException e) Z|ZB6gP>h1
{ urCTP.F
e.printStackTrace (); ~{vB2
} kY{$[+-jR
LNHi}P~
{ w sT
return n; i27)c)\BM
} b`^Q ':^A
:g^ mg-8
TOS'|xQ
} dh&>E
[+xsX*+
S9r+Nsn
/* v_WQ<G?
**SiteInfoBean.java U/|JAg#
*/ D>HbJCG4^
package NetFox; $&KkZ
|d*a~T0
lmD[Cn
public class SiteInfoBean { pIYXYQ=Z
.uxM&|0H
aJA(UN45
private String sSiteURL; //Site's URL R<{Vgy
private String sFilePath; //Saved File's Path ;z N1Qb
private String sFileName; //Saved File's Name +{I" e,Nk
private int nSplitter; //Count of Splited Downloading File zR]!g|;f
aW{5m@p{"
x-%RRm<V
public SiteInfoBean() ftl?x'P%
{//nSplitter的缺省值为5 M6Np!0G
//default value of nSplitter is 5 5$cjCjY
this("","","",5); w-LENdw
} :2,NKdD
\hBzP^*"n
VO=Ibu&X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) uZ\+{j=
{ Z*UVbyC
sSiteURL= sURL; .kPNWNrw
sFilePath = sPath; gt02Csdt
sFileName = sName; 150-'Q
this.nSplitter = nSpiltter; _*Z3,*~"X
e6J^J&`|4
7Zdg314
} -57~7 <N
9:-7.^`P
\]5I atli
public String getSSiteURL() /sT?p=[.
{ ctLNzJes%
return sSiteURL; f% )9!qeW
} BK6 X)1R
} e+`Kxy
>0<n%V#s:r
public void setSSiteURL(String value) 5Pn.c!
{ %DXBl:!Y`
sSiteURL = value; A8Fe@$<#8
} Vdd
x-X~'p'f
BI%XF 9{
public String getSFilePath() HG?+b
{ Fs%`W4/
return sFilePath; .SER,],P
} C c:<F_UI
Sp:w _;{#
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public void setSFilePath(String value) <r t$~}
{ +qC[X~\
sFilePath = value; ]S[?tn
} 0F/[GZ<k
3]mprX'
T]-MrnO
public String getSFileName() ~"SQwE|
{ 09jE7g @X}
return sFileName; LR>s2zu-
} !U m9ceK
vIOGDI>
K.Y`/<
public void setSFileName(String value) ,1N|lyV
{ [X!w@d= i
sFileName = value; PS+~JwDUc
} NLG\*mQ
Q!V:=d
S_Wq`I@b
public int getNSplitter() "V26\
{ s_VcC_A
return nSplitter; 9*ZlNZ
} >$L7J=Em
igk<]AwxS
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public void setNSplitter(int nCount) L-D4>+
{ ob;|%_
nSplitter = nCount; 2[qfF6FHA
} vB_3lAJt@
} ~nfOV*
w3);ZQ|
86Q3d%;-yo
/* 2J&~b8:
**Utility.java >WDHRC
*/ kexV~Q
package NetFox; e7xBi!I)~
oYZ 4F
n>j2$m1[
public class Utility { :e;6oC*"q
DlE,aYB
$">j~!'
public Utility() kF~(B]W(
{ k/wD@H N
qfE0J;e
cVL|kYVWT
} 7`;sX?R
W wPzm?30
//线程睡眠 K8X7IE
public static void sleep(int nSecond) f/#Id]B
{ 'A7!@hVy
try{ n2B%}LLa
Thread.sleep(nSecond); 1?FG3X 5
} DMG~56cTO,
catch(Exception e) /ta}12Z
{ KxX[8
e.printStackTrace (); >aO.a[AM
} c2M
} tSJ#
W?.469yy
//日志 7UMZs7L$
public static void log(String sMsg) 0HoHu*+FX
{ pS ](Emn`.
System.err.println(sMsg); :)lG}c
} |di(hY|
NknS:r&2
) bI.K[0^
public static void log(int sMsg) O?Bf (y
{ v7 *L3Ol
System.err.println(sMsg); nXLz<wE
} ?o;ip
} Mu[lk=jC
#:gl+
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/* KQNQ<OE4
**TestMethod.java [q2:d^_FA
*/ JfN '11,$
package NetFox; 4@{cK|
d/Q#Z
F~ 5,-atDM
public class TestMethod { 3LLG#l)8
3&^hf^yg
7 mCf*|
public TestMethod() 5:IDl1f5
{ ///xx/weblogic60b2_win.exe -eF-r=FR
try{ .h=n [`RB
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); //2O#Fg{/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?pW1}:z
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;um)JCXz
fileFetch.start(); O>]i?
} BJux5Nh
catch(Exception e){e.printStackTrace ();} r{R<J?Y
);d07\V
.t1:;H b
} w{*kbGB8s7
KSchgon0V
qKfUm:7Q_
public static void main(String[] args) eavn.I8J
{ Ra|P5
new TestMethod(); qhGz2<}_j
} _HHvL=
} #kM|!U=
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