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)); gBYL.^H^l
} Hi,_qlc+
for(int i=0;i<nEndPos.length-1;i++) m ~fqZK
{ y<BiR@%,7
nEndPos = nStartPos[i+1]; A{x&5yX8
} q,aWF5m@
nEndPos[nEndPos.length-1] = nFileLength; +**H7: bO
} iBN,YPo~
} 9^v|~f
?Sn$AS I
;L(W'+
//启动子线程 ?7^('
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7fI[yCh
for(int i=0;i<nStartPos.length;i++) kzJNdYtdH
{ 6}C4 SZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U+@yx>!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^=OjsN
nStartPos,nEndPos,i); eJ'2CM6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jc`LUJT
fileSplitterFetch.start(); Ip.5I!h[Xb
} 7Ar4:iNvX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *: e^yi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %j2YCV7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eK/[jxNO
nEndPos = " + nFileLength); U QXT&w
// fileSplitterFetch[nPos.length-1].start(); .X_k[l9
7<IrN\@U
bxkp9o
//等待子线程结束 1'c!9
//int count = 0; {(D$Xb
//是否结束while循环 [GhT.
boolean breakWhile = false; Y&Pi`E9=
Yx(?KN7V?
OjJlGElw
while(!bStop) (mt,:hX
{ E|6X.Ny]
write_nPos(); fU>"d>6!S
Utility.sleep(500); i&mu=J[
breakWhile = true; Z=825[p
VG2TiR1
;]Y.2 J
for(int i=0;i<nStartPos.length;i++) ZS>}NN
{ m[ay
if(!fileSplitterFetch.bDownOver) /Wg$.<!5}
{ g@MTKqs
breakWhile = false; G A2S
break; ouVR[w>V
} kn+`2-0
} jBI VZ!X
if(breakWhile) w^G<]S{l
break; |;OM,U2
ZN%$k-2
?Q9/C|
//count++; ,GVHwTZ0`
//if(count>4) kSB)}q6a
// siteStop(); RBt"7'
} /}#z/m@bN
S@N&W&W#~
l:j9lBS
System.err.println("文件下载结束！"); D'Byl,W$
} Uk|Xs~@#E
catch(Exception e){e.printStackTrace ();} B`"-~4YAf
} OR1XQij
+P}'2tE~'
:!g|0CF_
//获得文件长度 ^4B6IF*
public long getFileSize() yK"U:X
{ i @+Cr7K,
int nFileLength = -1; 7" Dw4}T
try{ e3)rF5pp
URL url = new URL(siteInfoBean.getSSiteURL()); C*kZ>mbc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,dzbI{@6
httpConnection.setRequestProperty("User-Agent","NetFox"); 2#T|+mKxZM
r'{pTgm#
f+fF5Z\
int responseCode=httpConnection.getResponseCode(); Pa0tf:
if(responseCode>=400) jY87NHg
{ s67$tlV
processErrorCode(responseCode); 0/{-X[z
return -2; //-2 represent access is error aJI>qk h?]
} S U2`H7C*
1tQZyHc42;
#3kR}Amow
String sHeader; 53BXz= k
WAqR70{KM
#mx;t3ja7
for(int i=1;;i++) RL.%o?<&?
{ +Nc|cj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sGMC$%e}
//Utility.log(in.readLine()); [gIStKe
sHeader=httpConnection.getHeaderFieldKey(i); |I)xK@7
if(sHeader!=null) iu*u|e
{ pOIFO=k
if(sHeader.equals("Content-Length")) +;FF0_
{ `!!A;G7Qg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h^x7[qe
break; d/P$qMD
} UO<uG#FB
} 0<!kGL5
else s:I^AL5
break; -uy}]s5Qu
} yq6!8OkF
} !QcgTW)T
catch(IOException e){e.printStackTrace ();} lSXhHy
catch(Exception e){e.printStackTrace ();} >=C)\Yfu)
XRP/E_4
a^4(7
Utility.log(nFileLength); d@,q6R}!MP
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9dqD(S#C;"
return nFileLength; 2=F_<Jh|+
} -}4H'%Z(i
Yk?uxZ4)H
+-qD!(&-6
//保存下载信息（文件指针位置） '~3(s?B
private void write_nPos() cX*
{ 78qf
try{ LP=!u~?
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0IQu6 X
output.writeInt(nStartPos.length); 5jx{O${u
for(int i=0;i<nStartPos.length;i++) OK3B6T5w=
{ eA{,=,v)
// output.writeLong(nPos); ;E*^AW
output.writeLong(fileSplitterFetch.nStartPos); 9L!Vj J
output.writeLong(fileSplitterFetch.nEndPos); 4.H!rkMM
} ``aoLQc`
output.close(); >%Y.X38Z[
} >s[}f6*2@
catch(IOException e){e.printStackTrace ();} Oo rH
catch(Exception e){e.printStackTrace ();} Wd~}O<"
} 7@+0E2'
s_D7?o
K8284A8v
//读取保存的下载信息（文件指针位置） 'Nfg%)-N
private void read_nPos() 1D=My1B
{ I0Wn?Qq=@
try{ Haq23K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zx=A3I%7 A
int nCount = input.readInt(); 1REq.%/=
nStartPos = new long[nCount]; >6jyd{
nEndPos = new long[nCount]; R`TM@aaS:
for(int i=0;i<nStartPos.length;i++) [>C^ 0\Z~
{ ag|d_;
nStartPos = input.readLong(); mI0|lp 1$
nEndPos = input.readLong(); ks(PH6:]<
} pSV 8!
input.close(); G=yQYsC$
} Jv7 @[<$
catch(IOException e){e.printStackTrace ();} r~t&;yRv
catch(Exception e){e.printStackTrace ();} P3lNns3
} 4fP>;9[F
r10)1`[
2<u vz<B
private void processErrorCode(int nErrorCode) Z(xn-
{ V :d/;~
System.err.println("Error Code : " + nErrorCode); rp(`V@x3
} &,NHk9.aq
YdC:P# Nf
]S;e#u{QE
//停止文件下载 f)"O( c
public void siteStop() e[Q(OV5(R
{ 8&dmH&
bStop = true; 0Apvuf1
for(int i=0;i<nStartPos.length;i++) M{O2O(
fileSplitterFetch.splitterStop(); 5 0~L(<
{(xNC#
'|WMt g
} #-e3m/>
} 8&`s wu&
//负责部分文件的抓取 j}0*`[c
**FileSplitterFetch.java <`6-J `.
*/ joM98H@
package NetFox; j q1qj9KZ
K")-P9I6-f
W]6Y buP:
import java.io.*; Yng9_w9Y
import java.net.*; b3Y9
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sjShm
public class FileSplitterFetch extends Thread { CgEeO,N]j
7p u*/W~
tk1qgjE(?
String sURL; //File URL +twBFhS7k
long nStartPos; //File Snippet Start Position BT`/OD@
long nEndPos; //File Snippet End Position < >f12pu
int nThreadID; //Thread's ID {yspNyOx
boolean bDownOver = false; //Downing is over /\#qz.c2K
boolean bStop = false; //Stop identical N;Hf7K
FileAccessI fileAccessI = null; //File Access interface %v}:#_va]
.HGEddcC
8V~w3ssz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XPWK"t01
{ mYa0_P%^
this.sURL = sURL; ~^Vt)/}Q
this.nStartPos = nStart; HnOp*FP
this.nEndPos = nEnd; kw=+"U
nThreadID = id; A:NsDEt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WdIr3
} hnE@+(d=qJ
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public void run() {#Gr=iv~N
{ <V>vDno\
while(nStartPos < nEndPos && !bStop) tYmWze.j
{ S~Nx;sB
<niHJ*
'%K,A-7W
try{ %li'j|
URL url = new URL(sURL); <([o4%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u!{P{C
httpConnection.setRequestProperty("User-Agent","NetFox"); q;B-np?U
String sProperty = "bytes="+nStartPos+"-"; '1.T-.4>&
httpConnection.setRequestProperty("RANGE",sProperty); ?CmW{9O
Utility.log(sProperty); NSM-p.I9
!>t|vgW
rJ!xzge;G
InputStream input = httpConnection.getInputStream(); c*1B*_08
//logResponseHead(httpConnection); 3(FJ<,"D}
'lIT7MK
:/Sx\Nz78
byte[] b = new byte[1024]; M[TgNWl/[
int nRead; eJJvEvZ,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }tj@*n_
{ UyK|KL
nStartPos += fileAccessI.write(b,0,nRead); $ n 7dIE
//if(nThreadID == 1) B8B^@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^>k[T.
} gX6'!}G8]
m_(+-G
_W?}%;
Utility.log("Thread " + nThreadID + " is over!"); oN)K2&M0
bDownOver = true; :X2B+}6_&
//nPos = fileAccessI.write (b,0,nRead); c&F"tLl
} t;y>q
catch(Exception e){e.printStackTrace ();} . 6Bz48*
} S ._9
} c9f~^}jNb
G}f.fRY
H!oP!rzEo
//打印回应的头信息 y4M<L. RO
public void logResponseHead(HttpURLConnection con) H>_%ZXL
{ YSv\T '3
for(int i=1;;i++) bU_9GGG|
{ HjV83S;
String header=con.getHeaderFieldKey(i); :K2N7?shA
if(header!=null) W13$-hf9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UY)YhXW
Utility.log(header+" : "+con.getHeaderField(header)); JH<q7Y6!y
else Ybd){Je"z
break; *"1]NAz+
} c%i/ '<Afr
} 2r[Q$GPM<
D97oS!*
SDdK5@1O4o
public void splitterStop() bl}$x/
{ ~?[@KK
bStop = true; 9e8@0?0
} oa;[[2c
=_L"x~0I-
1Qf5H!5vx
} Mgf80r=
t{84ioJ"$
hDVD@b
/* <\Y>y+$3
**FileAccess.java b6);bX>e
*//文件访问(定位，写) pm<<!`w"
package NetFox; }$m_):t@@
import java.io.*; PO |p53
{WFYNEQ[
R2u[IVZW:-
public class FileAccessI implements Serializable{ E})PNf;
C{Aeud #5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y>Nlj%XH
RandomAccessFile oSavedFile; .KRh59yg
long nPos; D~2,0K
?]$.3azO
m,)Re8W-
public FileAccessI() throws IOException (Dc dR:/=
{ N}.h_~6
this("",0); p3sz32RX
} hQHV]xW
h2uO+qEsu
x?Q;o+2v
public FileAccessI(String sName,long nPos) throws IOException jY$|_o.4
{ -41L^Di\
oSavedFile = new RandomAccessFile(sName,"rw"); .}a@OLJd
this.nPos = nPos; YZ/mTQn_D
oSavedFile.seek(nPos); KX`MX5?x
} 5/neV&VcB
}Y<(1w
5_=&U-? H
public synchronized int write(byte[] b,int nStart,int nLen) -FE5sW
{ KDHR}`
int n = -1; xa!@$w=U&
try{ e2/[`k=7-
oSavedFile.write(b,nStart,nLen); pMs%`j#T
n = nLen; ]RGun GJ
} %;ny
catch(IOException e) :vV?Yv%P)n
{ bpKb<c
e.printStackTrace (); !f_Kq$.{
} Q.vtU%T
z2nDD6N
F>!fu.Ws
return n; g($y4~#
} N2q'$o
~-'nEATE
aD%")eP%&
} X0P<ifIv
C]eb=rw$
P#76ehR]K
/* Pf(z0o&
**SiteInfoBean.java 5 _] i==M
*/ ydoCoD w
package NetFox; u~a<Psp&|
'nW:2(J
R},mq&f5
public class SiteInfoBean { 2b3x|9o8
Y}e$5
Xj|j\2$ 0
private String sSiteURL; //Site's URL ;QW)tv.y
private String sFilePath; //Saved File's Path &({X9
private String sFileName; //Saved File's Name 9>[$;>
private int nSplitter; //Count of Splited Downloading File 6VCw>x
vgsu~(L;
IvH0sS`F
public SiteInfoBean() MPNBA1s
{//nSplitter的缺省值为5 bha_bj
//default value of nSplitter is 5 iOzw)<
this("","","",5); % sT=>\
} ^Z2%b>
cl14FrpYu
?XW+&!ar
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2nOQ48haT
{ RwY) O5
sSiteURL= sURL; &eg]8kV
sFilePath = sPath; #Wh"_zpM+
sFileName = sName; gp(w6:w
this.nSplitter = nSpiltter; S(/@.gI:f
*|hICTWL
\XmtSfFC
} MqXA8D
rd. "mG.
Q:@Y/4=
public String getSSiteURL() va#~ \%`
{ %qN8uQx
return sSiteURL; EMJio\
} GawLQst[+
ZLo3 0*
sveFxI
public void setSSiteURL(String value) tA'i-D&
{ <>2QDI6_
sSiteURL = value; )3z.{.F
} 31J7# S2
Fda<cS]
)lH?XpfTjm
public String getSFilePath() 5.5dB2w
{ ilpg()
return sFilePath; zg|yW6l)9
} 9;JUc0%
qlDLZ.
pOw4H67
public void setSFilePath(String value) }]tSWVb*
{ {s_0[>
sFilePath = value; b!_l(2
} dp_J*8
WET $H,
5%,n[qj4IT
public String getSFileName() .DCp)&m l;
{ l,sYYU+iY
return sFileName; $F\&?B1.
} %Sxy!gGz%%
\h_hd%'G
${e(#bvGZ
public void setSFileName(String value) $?I^Dk
{ 9$S2:2(G
sFileName = value; 0*q~(.>a
} @AVx4,!>[
,CwhpW\Y
;2%3~L8?V
public int getNSplitter() [y>Q3UqN
{ /rJvw
return nSplitter; 9.PY49|
} ;41s&~eR
$3"0w
Zp]Bs
public void setNSplitter(int nCount) t_P1a0Zu
{ 28Q`O$=v
nSplitter = nCount; 4#4kfGoT
} uA\A4
} v }P~g
;#f_e;
j:U>V7Kn3~
/* z,/dYvT<
**Utility.java 6o6!Ol
*/ zM[WbB+"m
package NetFox; [o|]>(tk
^k u~m5v
hFQC%N.'
public class Utility { Zad+)~@!tq
-cIc&5CS
yf_<o
public Utility() '_(oa<g
{ QZQ@C#PR;
g/VC$I!'
BAqu@F\):
} q_HD`tW
9n9/[?S
//线程睡眠 QF-.")Z
public static void sleep(int nSecond) 1mA)=hu
{ ?;uzx7@F
try{ .[K{;^>
Thread.sleep(nSecond); 9HP)@66
} Oi l>bv8
catch(Exception e) 1Kwl_jf
{ ilFM+x@
e.printStackTrace (); RAf+%h*
} @A$%baH0
} @/|sOF;8W
NP%ll e,l
//日志 y"7TO#
public static void log(String sMsg) G++kUo<
{ B}r@xz
System.err.println(sMsg); D.$EvUSK<.
} Xb|hP
X,T^(p
@LwhQ
public static void log(int sMsg) sM~CP zMa
{ +R#*eo;o7
System.err.println(sMsg); Nnv&~D>
} ,0#OA*0B
} `.[hOQ7
GlD@Ud>o)
nJ2l$J<
/* a$9UUH-|
**TestMethod.java T_YN^za(q
*/ UPJgTN*
package NetFox; YXD1B`23
Eb{TKz?
KHF5Nt
public class TestMethod { <<n8P5pXt
F!aYK2
~{+J~5!;<H
public TestMethod() t7)Y@gRy
{ ///xx/weblogic60b2_win.exe S :(1=@
try{ qJISB7F[%O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^Ko0zz|R/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %}$6#5"';
SiteFileFetch fileFetch = new SiteFileFetch(bean); |fRajuA;
fileFetch.start(); )xTp7YnZ;
} bh+R9~
catch(Exception e){e.printStackTrace ();} ed\,FWR
'7_'s1
_^&oNm1
} NK"y@)%0
D8Ni=.ALL
I`5MAvP
public static void main(String[] args) 5Vut4px
{ "q]v2t
new TestMethod(); u45e>F=
} TR ]lP<m
} YK"({Z>U
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