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)); %VzCeS9
} pS<j>y
for(int i=0;i<nEndPos.length-1;i++) 9y&&6r<I
{ GH6ozWA
nEndPos = nStartPos[i+1]; 9|LV x3]
} ,W&::/2<7
nEndPos[nEndPos.length-1] = nFileLength; "+ 8Y{T
} dI9u:-
} hXsH9R
wfF0+T+IA
"( P-VX
//启动子线程 ye1hcQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %'i`Chc^!;
for(int i=0;i<nStartPos.length;i++) 5"&{Egc_
{ zJa,kN|m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {nlqQ.jO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ){{]3r
nStartPos,nEndPos,i); qx3`5)ef
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lip1wR7
fileSplitterFetch.start(); N|L Ey
} VWR6/,N^_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h$y0>eMWs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :raYt5n1,y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~Uw<E:?v
nEndPos = " + nFileLength); 00)=3@D
// fileSplitterFetch[nPos.length-1].start(); 8HymkL&F
]f"l4ay@M
u|a+:r)*4
//等待子线程结束 \%D/]"@r
//int count = 0; 8 m T..23
//是否结束while循环 w-.=u3
boolean breakWhile = false; @`6db
R@)L@M)u;
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while(!bStop) Pq:GvM`
{ $5)ZaYx<
write_nPos(); ?YO$NYwE
Utility.sleep(500); s&7,gWy}BE
breakWhile = true; fhZD[m#D
aD,(mw-7r
aZMMcd
for(int i=0;i<nStartPos.length;i++) ,3`RM$
{ z"C+r'39d=
if(!fileSplitterFetch.bDownOver) Jj$N3UCg7
{ $`&uu
breakWhile = false; >=_Z\ wA
break; . !|3a
} +EWfsKz
} do:3aP'S,
if(breakWhile) Q'~2,%3<
break; aQK>q. t
0{PRv./`
)NwIEk>Tf
//count++; c?NXX&
//if(count>4) :u7y k@
// siteStop(); rU/V~;#%
} EfR3$sp
JPX5Jm()
gt1W_C\
System.err.println("文件下载结束！"); 5mD]uB9
} K0i[D"
catch(Exception e){e.printStackTrace ();} X=<-rFW
} F~cvob{
Rmrv@.dr!
ly<1]jK
//获得文件长度 4$+9Wv
public long getFileSize() ,rB"ag !
{ mE"?{~XVL
int nFileLength = -1; HY,+;tf2r
try{ :dtX^IT
URL url = new URL(siteInfoBean.getSSiteURL()); /=zzym~<>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L+}q !'8S
httpConnection.setRequestProperty("User-Agent","NetFox"); =U6%Wdth
l%?D%'afN
t$sL6|Ww}o
int responseCode=httpConnection.getResponseCode(); >4A~?=
if(responseCode>=400) / ;U
{ l@8UL</W
processErrorCode(responseCode); HCh;Xi
return -2; //-2 represent access is error w !N;Y0
} ?d*0-mhQ,
/-ebx~FX&
ZI q!ee
String sHeader; . mDh9V5
s}]qlg
P&@:''
for(int i=1;;i++) tdTD!'
{ ;* vVucx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c$)Y$@D
//Utility.log(in.readLine()); E$-u:Z<-
sHeader=httpConnection.getHeaderFieldKey(i); Yq;|Me{h
if(sHeader!=null) [TAW68f'
{ W|K"0ab
if(sHeader.equals("Content-Length")) Th&* d;
{ a D*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o#KGENd
break; x/NR_~Rnk
} VZ?"yUZ Id
} \bze-|C
else ({#9gTP2b
break; y$VYWcFE
} 8Z TN
} $]4>;gTL'
catch(IOException e){e.printStackTrace ();} $MF U9<O
catch(Exception e){e.printStackTrace ();} ), >jBYMJ
wD}ojA&DU
3PB#m.N<
Utility.log(nFileLength); Y}_J@&:
;P9P2&c8c
`I(#.*
return nFileLength; ~$1Zw&X
} GY@-}p~it
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?*i qg[:
//保存下载信息（文件指针位置） G.2ij%Zz
private void write_nPos() cPh U qET
{ ]Mu + DZ
try{ 5!2^|y4r
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2ZMYA=[!
output.writeInt(nStartPos.length); d'~sy>
for(int i=0;i<nStartPos.length;i++) +@]b}W
{ c+l1#[Dnc
// output.writeLong(nPos); 0GR\iw$[J
output.writeLong(fileSplitterFetch.nStartPos); 0MK|spc
output.writeLong(fileSplitterFetch.nEndPos); 6Q<^,`/T
} =`f6@4H
output.close(); E DuLgg@
} 14TA( v]T
catch(IOException e){e.printStackTrace ();} 6LUO
catch(Exception e){e.printStackTrace ();} F+A"-k_\T#
} 'p=5hsG
R:zPU
Nz`4q%+
//读取保存的下载信息（文件指针位置） oQgd]|v
private void read_nPos() M_tY:v
{ ]3@6o*R;
try{ csg:#-gE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `UFRv
int nCount = input.readInt(); e)dPv:oK3
nStartPos = new long[nCount]; "(y",!U@
nEndPos = new long[nCount]; TJ@@kSSbl
for(int i=0;i<nStartPos.length;i++) %(a<(3r
{ lWS@<j
nStartPos = input.readLong(); BIf E+L(
nEndPos = input.readLong(); NG-Wn+W@b
} :'aT4
input.close(); 1iq,Gd-G.
} 5t]}(.0+
catch(IOException e){e.printStackTrace ();} \|20E51B[
catch(Exception e){e.printStackTrace ();} 7;dTQ.%n
} t0_o.S
-lHSojq~H
5urM,1SQ@
private void processErrorCode(int nErrorCode) qd*3| O^
{ -x~h.s,
System.err.println("Error Code : " + nErrorCode); 4`lt 4L
} dR"H,$UH
'N$hbl
,]?Xf>
//停止文件下载 pKDP1S#<
public void siteStop() OgJd^
{ K;jV"R<9
bStop = true; OjxaA[$
for(int i=0;i<nStartPos.length;i++) ;-p1z% u
fileSplitterFetch.splitterStop(); FQdz":5
`ER">@&
DDkH`R
} w~J 7|8Y
} m1@ste;$W
//负责部分文件的抓取 $o rN>M42
**FileSplitterFetch.java ~l$u~:4Ob
*/ &$yC+cf
package NetFox; ySP1,xq
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Oo'IeXQ9(
import java.io.*; %H=d_Nm{
import java.net.*; utIR\e#:B
MhMY"bx8
~!( (?8"
public class FileSplitterFetch extends Thread { q$)$?"
OiI[w8
5W/!o&x~7
String sURL; //File URL 40TS=evG
long nStartPos; //File Snippet Start Position tL0<xGI5^
long nEndPos; //File Snippet End Position r[xj,eIb
int nThreadID; //Thread's ID a12Q/K
boolean bDownOver = false; //Downing is over ~`'!nzP5H
boolean bStop = false; //Stop identical W}&[p=PAS
FileAccessI fileAccessI = null; //File Access interface r*#ApM"L
^z&eD,
]IbX<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hdky:2^3
{ Xv[5)4N
this.sURL = sURL; ovv<7`
this.nStartPos = nStart; @<]sW*s
this.nEndPos = nEnd; g)7~vm2/,
nThreadID = id; N$1ZA)M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z~[:@mGl
} p<b//^
%@/"BF;r
0k]$ he;h
public void run() I'&#pOB
{ <9zzjgzG{c
while(nStartPos < nEndPos && !bStop) YbaaX{7^
{ ;Du+C%
p,_,o3@~
Co|3k:I 8
try{ #_]/Mr1
URL url = new URL(sURL); >uVo'S.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4n55{?Z
httpConnection.setRequestProperty("User-Agent","NetFox"); aYTVYg
String sProperty = "bytes="+nStartPos+"-"; Ze `=n
httpConnection.setRequestProperty("RANGE",sProperty); P2HR4`c
Utility.log(sProperty); iuxI$
XO[S(q
O~3<P3W
InputStream input = httpConnection.getInputStream(); iBCZx>![;
//logResponseHead(httpConnection); C\%T|ZDE
yV{&x
L`sg60z
byte[] b = new byte[1024]; Hzm<KQ g
int nRead; |tK_Bn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Xe;Eu
{ 2xPkQOj3
nStartPos += fileAccessI.write(b,0,nRead); ;/ wl.'GA
//if(nThreadID == 1) 9;W2zcN
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PE!/n6
} X#;n Gq)5
VU8EjuOetb
G6W_)YL
Utility.log("Thread " + nThreadID + " is over!"); \"]KF8c^_
bDownOver = true; %"<|u)E
//nPos = fileAccessI.write (b,0,nRead); /-J
} E6 g]EE
catch(Exception e){e.printStackTrace ();} IP?15l w
} =sm<B^yj
} r4YiXss
QoLp$1O(y
"|N58%
//打印回应的头信息 "0*yD[2
public void logResponseHead(HttpURLConnection con) Uu_g_b:z
{ ON(OYXj
for(int i=1;;i++) @euH[<
{ |Do+=Gr$t@
String header=con.getHeaderFieldKey(i); 3!l+)g
if(header!=null) /Dd.C<F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $ol]G`+
Utility.log(header+" : "+con.getHeaderField(header)); D=+md
else R"wBDWs
break; XC(:O(jdA2
} (6}[y\a+
} J#>)+
[Xa,|
lr*p\vH
public void splitterStop() |?cL>]t
{ bUzo>fm_
bStop = true; Wtwo1pp
} Ir\P[A
f]pHJVgFV
qix$ }(P
} P,Z K
/IxoS
JpRn)e'Z
/* [S~/lm
**FileAccess.java Ao )\/AR'
*//文件访问(定位，写) Af"p:;^z
package NetFox; ~hZr1hT6L
import java.io.*; 1^ijKn@6
U#iGR5&^3
NR>&1aRbyb
public class FileAccessI implements Serializable{ P5JE = &M
}6'%p Bd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kOE\.}~4
RandomAccessFile oSavedFile; HJi FlL3
long nPos; \N%L-%^
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2/iBk'd
public FileAccessI() throws IOException &At9@
{ [;C|WTYSL
this("",0); y$}o{VE{x
} 4wkmgS
^, &'
&s(mbpV
public FileAccessI(String sName,long nPos) throws IOException {/|tVc63
{ zNO,vR[\
oSavedFile = new RandomAccessFile(sName,"rw"); HEk{!Y
this.nPos = nPos; U]]ON6Y&F
oSavedFile.seek(nPos); nb\pBl
} ~<Z7\yS)
cCuK?3V4K
=E$B0^_2RC
public synchronized int write(byte[] b,int nStart,int nLen) -l~+cI\2
{ NI:3hfs
int n = -1; V}MRdt7
try{ K8JshFIe
oSavedFile.write(b,nStart,nLen); "$nff=]
n = nLen; |\U5m6q
} M1q_gHA
catch(IOException e) =3Ohy,5L
{ Fr_6pEH]}
e.printStackTrace (); sE])EwZ
} P9o=G=i
oO^=%Mc(
1=_Qj}!1
return n; cl'wQ1<:
} G-TD9OgZ
hvc3n> Y[}
9DmFa5E
} fCbd]X
hs*n?vxp3
vO)]~AiB
/* qi['~((
**SiteInfoBean.java j6E|j>@u
*/ 1pz-jo,2'
package NetFox; o;u~Yg
E5IS<.
.JBTU>1]_n
public class SiteInfoBean { 2v<O}
y"|gC!V}
3TRG] 5
private String sSiteURL; //Site's URL 2%/+r
private String sFilePath; //Saved File's Path _`.Q7
private String sFileName; //Saved File's Name -6xh
private int nSplitter; //Count of Splited Downloading File |zJ2ZE|
TU*Y?D L
HLCI
public SiteInfoBean() ?ph>:M
{//nSplitter的缺省值为5 ZA\;9M=
//default value of nSplitter is 5 6$K@s
this("","","",5); 7b7WQ7u
} K,,'{j2#f
+(Jh$b_
yG^pND>_df
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #itZ~tol
{ \x|8
sSiteURL= sURL; ]!uId#OH
sFilePath = sPath; >[ g=G
sFileName = sName; _Nh`-R%B)
this.nSplitter = nSpiltter; pq:[`
X%T%N;P
7gx?LI_e
} VI-6t"l
6m@B.+1
Ph)>;jU
public String getSSiteURL() %a]Imsm
{ et/v/Hvw1
return sSiteURL; /iL*)
} x.sC015Id
agq4Zy
'>HLE)l
public void setSSiteURL(String value) :sttGXQX
{ #|T2`uYotf
sSiteURL = value; ,b:~Vpb1I
} }D-jTZlC
f`iDF+h<6
[c XSk
public String getSFilePath() #N;&^El
{ c& K`t
return sFilePath; =G !]_d0
} 7GCxd#DJ
nb ?(zDJ8
pK ^$^*#
public void setSFilePath(String value) <+<Nsza
{ QP<.~^ao
sFilePath = value; W0}FOfL9
} c|K:oi,z
S~R[*Gk_uT
li{!Jp5]1b
public String getSFileName() z`p9vlS[
{ #. 71O#!
return sFileName; .Hk.'>YR
} @>8{J6%\
y(#6nG@S
:^-\KE`3
public void setSFileName(String value) aMVq%{U
{ 0{I-x^FI
sFileName = value; /x4L,UJ= P
} `Y^l.%AZZ
#<s"?Y%-
`5"3Cj"M
public int getNSplitter() X\>/'fC$
{ KzJJ@D*4M]
return nSplitter; g1:%986jv
} EB@rIvUi,
ZAn9A>5_
T%;NW|mH&
public void setNSplitter(int nCount) ,gM:s}l!dJ
{ 6!N2B[9
nSplitter = nCount; @sW!g;\T
} LDYa{w-t
} ?b"'w
OmK4 \_.
awjAv8tPO!
/* L}'^FqO[IW
**Utility.java TQPrOs?
*/ ]h=5d09z
package NetFox; /8Z&Y`G
6L)7Q0Z
V-E 77u6{0
public class Utility { 6'.)z,ts
AX Q.E$1g
Xbrc_V\_
public Utility() PHUeN]s#
{ Mz86bb^J
jQ7-M4qO/
Ix<!0! vk
} mx}4iO:Xp
>_G'o
//线程睡眠 ruyQ}b:zS
public static void sleep(int nSecond) 2\1bQq\
{ TP~1-(M)}
try{ wAJ=rRI
Thread.sleep(nSecond); fVVD}GM=
} mlUj%:Gm#
catch(Exception e) mahNQ5W*)
{ @ &Od1X
e.printStackTrace (); z@V9%xF-3
} lN0u1)'2
} ,oPxt
@,-D P41g
//日志 rvK%m_r
public static void log(String sMsg) x9S9%JG :
{ v(=0hY9 O
System.err.println(sMsg); "Nz@jv?
} }' sW[?ik
ZU;jz[}
{"2CI^!/U.
public static void log(int sMsg) Qw }1mRv
{ ao[yHcAs
System.err.println(sMsg); F%af05L[
} pd& HC
} ):}A Quy]
Cud!JpL
GCX?W`
/* M%W#0
**TestMethod.java {MTtj4$
*/ ;:+2.//
package NetFox; =dQ/^C_hj
kHhku!CH
z|Yt|W
public class TestMethod { t}?-ao
6Z2|j~
<h}x7y?
public TestMethod() o~q.j_Sa
{ ///xx/weblogic60b2_win.exe r4fg!]J;
try{ DlAwB1Ak
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @LDs$"f9=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0vBQzM Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); mV)t
fileFetch.start(); 6A}tA$*s7
} Q9B!0G.-bs
catch(Exception e){e.printStackTrace ();} XW@C_@*J
&GvSgdttv
yLK %lP
} {fX~%%c"
Ro<x#Uo
2tCw{Om*
public static void main(String[] args) &-JIXVd*R
{ 1$6 u
new TestMethod(); [z+YXs!N
} _x#y
} ; C(5lD&\5
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