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)); xBg.QV
} CCU<t Q
for(int i=0;i<nEndPos.length-1;i++) ;eT+Ly|{
{ Or,W2
nEndPos = nStartPos[i+1]; >j_N6B!
} 1 JB~G7
nEndPos[nEndPos.length-1] = nFileLength; E 9v<VoNP`
} GLr7sack
} (V9 ;
b?nORWjC
D=:O^<
//启动子线程 j/uu&\e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2^4OaHY88
for(int i=0;i<nStartPos.length;i++) )l[bu6bM
{ Rxk0^d:sNi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i;mA|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H?tX^HO:q
nStartPos,nEndPos,i); l{4rKqtX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )k6kK}
fileSplitterFetch.start(); 'O[0oi&
} h#(J6ht
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m\e?'-(s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C5x*t Q|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7j8Ou3
nEndPos = " + nFileLength); -8m3L
// fileSplitterFetch[nPos.length-1].start(); 9q_c`
Ji7<UJ30x
D'<'"kUd
//等待子线程结束 bW^JR,
//int count = 0; V3c7F4\
//是否结束while循环 OS sYmF
boolean breakWhile = false; DZqY=Sze
vfloha p
pgEDh^[MW
while(!bStop) NGVl/Qd
{ {W$K@vuV;?
write_nPos(); (fcJp)D
Utility.sleep(500); -)Of\4kx
breakWhile = true; #VynADPs`o
/nB|Fo_&Q
B<oBo&uA
for(int i=0;i<nStartPos.length;i++) ^vha4<'-qG
{ e]-%P(}Z
if(!fileSplitterFetch.bDownOver) oUx%ra{
{ 0Ait7`
breakWhile = false; M*2 Nq=3
break; (Fs{~4T
} MZ"|Jn
} s"B+),Jod
if(breakWhile) )%vnl~i!
break; #dDM "s
lGpci
jH?!\F2)+
//count++; ED^0t
//if(count>4) aDda&RM
// siteStop(); uS7kkzt-x
} \h5!u1{L
oMHTB!A=2
6QAhVg: A
System.err.println("文件下载结束！"); ppzQh1
} t[o_!fmxZ
catch(Exception e){e.printStackTrace ();} a6!|#rt
} t4Pi <m:7
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FA!!S`{\
//获得文件长度 ()e|BFL.
public long getFileSize() RAj>{/E#W
{ h]pz12Yf
int nFileLength = -1; vW4n>h}]
try{ AL;4-(KH
URL url = new URL(siteInfoBean.getSSiteURL()); %uDH_J|^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "NtY[sT{V
httpConnection.setRequestProperty("User-Agent","NetFox"); R*DQLBWc
v-DZW,
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int responseCode=httpConnection.getResponseCode(); t^~Qv
if(responseCode>=400) XeX`h_
{ d r$E:kr
processErrorCode(responseCode); nYE%@Up
return -2; //-2 represent access is error OXI>`$we
} ;b!qt-;.<
pv]" 2'aQ
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String sHeader; i>e?$H,/
%S/?Ci
1P?|.W_^1
for(int i=1;;i++) '9!J' [W
{ J?C:@Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u=t.1eS5
//Utility.log(in.readLine()); S?#6{rx
sHeader=httpConnection.getHeaderFieldKey(i); v1z d[jqk
if(sHeader!=null) %rJ'DPs
{ GA;h7
if(sHeader.equals("Content-Length")) oL@K{dk
{ (dTQ,0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !cW!zP-B*p
break; Up5|tx7
} E8BIb 'b;
} &O#,"u/q`
else fj'7\[nZ
break; )3k?{1:
} <QD[hO^/
} JJK-+a6cX
catch(IOException e){e.printStackTrace ();} Z@}qL1
catch(Exception e){e.printStackTrace ();} bvS6xU- J
3~:9ZWQ/
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Utility.log(nFileLength); [0vqm:P
IKV!0-={!z
0o!mlaU#
return nFileLength; 8Qhj_
} 3S" /l
,B'fOJ.2
.y<u+)
//保存下载信息（文件指针位置） |}b~YHTs
private void write_nPos() 7}vI/?r
{ kpXxg: c
try{ zd/kr
output = new DataOutputStream(new FileOutputStream(tmpFile)); me@)kQ8M
output.writeInt(nStartPos.length); DTG-R>y^
for(int i=0;i<nStartPos.length;i++) Jj?HOtaM
{ Q-z `rW
// output.writeLong(nPos); :W;eW%Y
output.writeLong(fileSplitterFetch.nStartPos); ;Y0M]pC
output.writeLong(fileSplitterFetch.nEndPos); ~r~YR=
} iBI->xU[U
output.close(); sNM ]bei
} ~d\^ynQ
catch(IOException e){e.printStackTrace ();} t YxN^VqU
catch(Exception e){e.printStackTrace ();} O_]hbXV0
} B<i(Y1n[
zK&1ti@wln
,3N>`]Km'
//读取保存的下载信息（文件指针位置） -E~r?\;X
private void read_nPos() L9-Jwy2(>
{ 4:-x!lt
try{ 7ug"SV6Hb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); HLOrDlj7
int nCount = input.readInt(); f;AI4:#I
nStartPos = new long[nCount]; 7hTpjox2
nEndPos = new long[nCount]; Jy\0y[f*
for(int i=0;i<nStartPos.length;i++) R9!U_RH
{ k||dX(gl
nStartPos = input.readLong(); &>&6OV]P'
nEndPos = input.readLong(); ln+.=U6Tm
} *V4%&&{
input.close(); Tdm|=xI
} 8i5S }
catch(IOException e){e.printStackTrace ();} {xeJO:M3/
catch(Exception e){e.printStackTrace ();} b$yIM
} s1h|/7gG
RMiDV^.u`
UI"UBZZ$
private void processErrorCode(int nErrorCode) 2gh=0%|\gx
{ |L`U2.hb
System.err.println("Error Code : " + nErrorCode); ;|0P\3
} >I/@GX/
;!G#Y Oe
$v #
//停止文件下载 /QWXEL/M=
public void siteStop() Y[]I!Bc
{ :)i,K>y3i
bStop = true; } C:i0Q
for(int i=0;i<nStartPos.length;i++) `hdff0
fileSplitterFetch.splitterStop(); 1YQYZ^11
AwjXY,2
ZuybjV1/f6
} m#8(l{3|
} kJpO0k9?eY
//负责部分文件的抓取 TY'c'u,
**FileSplitterFetch.java [T,Hpt
*/ (xHu@l!]
package NetFox; i1XRBC9
l5.k2{'
^lt2,x
import java.io.*; TA0(U$ 4
import java.net.*; A]TEs)#*7)
V?1[R
=yz"xWH
public class FileSplitterFetch extends Thread { #:+F
ti (Hx
57EX#:a
String sURL; //File URL Le:C8^
long nStartPos; //File Snippet Start Position [^s;Ggi9
long nEndPos; //File Snippet End Position s .<.6t:G4
int nThreadID; //Thread's ID G;flj}z
boolean bDownOver = false; //Downing is over q&J5(9]O|L
boolean bStop = false; //Stop identical $y&W:
FileAccessI fileAccessI = null; //File Access interface 8["%e#%`$
pZ}B/j
n1{[CCee@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i@.Tv.NZ
{ 8toOdh
this.sURL = sURL; sv?Fx;d
this.nStartPos = nStart; %~x?C4L8
this.nEndPos = nEnd; ah hl
nThreadID = id; "~0`4lo:Xo
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -fk;Qq3O
} '?| 1\j
+Wg/O -
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public void run() }x\#ul)
{ `-.2Z 0
while(nStartPos < nEndPos && !bStop) pB\:.?.pd
{ DqT<bNR1*;
Y(bB7tR
r'j88)^
try{ ij;NM:|Sd
URL url = new URL(sURL); \fUX_0k9,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z4Zm%
httpConnection.setRequestProperty("User-Agent","NetFox"); %jy$4qAf%
String sProperty = "bytes="+nStartPos+"-"; S4`X^a}pY
httpConnection.setRequestProperty("RANGE",sProperty); ` PQQU~^
Utility.log(sProperty); SMD*9&,
[U/h'A.j
v:/\;2
InputStream input = httpConnection.getInputStream(); NI#]#yM+
//logResponseHead(httpConnection); Fz';H
aqN{@|
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byte[] b = new byte[1024]; bf0,3~G,P
int nRead; o+&Om~W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JR#4{P@A
{ j :B/ FL
nStartPos += fileAccessI.write(b,0,nRead); #55:qc>m
//if(nThreadID == 1) 4qp|g'uXT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G(.G>8pf
} Ba8=nGa4KY
oG1zPspL
WM?-BIlT=
Utility.log("Thread " + nThreadID + " is over!"); W/bW=.d Jd
bDownOver = true; - [h[
//nPos = fileAccessI.write (b,0,nRead); F0p=|W
} X':FFD4h
catch(Exception e){e.printStackTrace ();} Ajm!;LA[jO
} =DJ:LmK
} G~8BND[."
TT/H"Ri}Jp
tngB;9c+w
//打印回应的头信息 n}.e(z_"
public void logResponseHead(HttpURLConnection con) Hs'~)T
{ nH?6o#]N
for(int i=1;;i++) \hgd&H0UU
{ P0}{xq'k9v
String header=con.getHeaderFieldKey(i); =yZq]g6Q
if(header!=null) Zh;wQCDj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }W8A1-UF
Utility.log(header+" : "+con.getHeaderField(header)); TPJF?.le '
else nK :YbLdK,
break; ah:["< z<
} b(GV4%
} dT*Yv`h
H5x7)1Ir|
Kh\ 7%>K#
public void splitterStop() UgGa]b[9A
{ 'wk,t^)
bStop = true; ?'6@m86d
} I?}jf?!oM
;,[0bmL
v#qdq!64
} 7-K8u
mG\QF0h
'Gl~P><e
/* z1Bi#/i
**FileAccess.java \L(cFjLIl
*//文件访问(定位，写) |qn2b=
package NetFox; ,~naKd.ZY
import java.io.*; g=$U&Hgs
8xO
8l5>t
public class FileAccessI implements Serializable{ [[IMf-]
Pl/ dUt_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c EYHB1*cT
RandomAccessFile oSavedFile; Gn8sB
long nPos; F)hj\aHm k
\t7yH]:>@
!6'N-b1
public FileAccessI() throws IOException Dhn7N8(LF!
{ nUP, Yd
this("",0); d=xjLbsZ
} _J!^iJ
h5'hP>b#
^1.*NG8
public FileAccessI(String sName,long nPos) throws IOException m}wn+R
{ T06(Q[)
oSavedFile = new RandomAccessFile(sName,"rw"); Q 84t=
this.nPos = nPos; (p%|F`
oSavedFile.seek(nPos); pz /[${X
} 7?=^0?a
XG.[C>
V+"%BrM
public synchronized int write(byte[] b,int nStart,int nLen) x8rg/y
{ =:s`C,l.4
int n = -1; US ALoe
try{ ;nBf
oSavedFile.write(b,nStart,nLen); +-@n}xb@
n = nLen; "V>}-G&
} %i9 e<.Ot
catch(IOException e) |MZ1j(_
{ T ?[28|
e.printStackTrace (); h+1|.d
} skcyLIb
`MSig)V
cuQ!"iH
return n; &!CVF
} 754MQK|g
T o["o!(;z
}d?;kt
} GJ*IH9YR
O%T?+1E
1<BKTMBq?{
/* M_ukG~/
**SiteInfoBean.java o0R?vnA=
*/ ur}'Y^0iR
package NetFox; B(;MI`
?@G s7'
,>-D xS
public class SiteInfoBean { blgA`)GI
27D*FItc
g3$'Ghf
private String sSiteURL; //Site's URL !{jw!bB
private String sFilePath; //Saved File's Path [Y](Y3/.N
private String sFileName; //Saved File's Name Qfn:5B]tI
private int nSplitter; //Count of Splited Downloading File #<*.{"T
Nbpn"*L,
dBXiLrEbs
public SiteInfoBean() [~{F(Le
{//nSplitter的缺省值为5 72sqt5C]
//default value of nSplitter is 5 2o?j{K
this("","","",5); U80=f2
} ,j*9)
i=Qy?aU?
'8;bc@cE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xvOz*vM?
{ ))=6g@(
sSiteURL= sURL; eC!=4_lx)
sFilePath = sPath; q%4X1 W
sFileName = sName; S oeoUI]m
this.nSplitter = nSpiltter; TGF$zvd
[K3 te
ev$:7}h=
} F\DiT|?}
VP#KoX85
C.S BJ
public String getSSiteURL() MI`qzC*%
{ w6V/Xp][U
return sSiteURL; ;|Mfq`s
} QOXo(S
3lp'U&3`5
Lm4`O%
public void setSSiteURL(String value) J>A9]%M
{ 01?+j%k=m/
sSiteURL = value; 6'^E ],:b
} ;TJpD0
n*7^lAa2
+c~&o83[
public String getSFilePath() ]:gW+6w"C
{ Ok_}d&A
return sFilePath; w#b@6d
} zQyI4RHG[
hBX*02p
M3jUnp&
public void setSFilePath(String value) Q6HJ+H-Ub
{ L/ 7AGR|;C
sFilePath = value; h <4`|Bg+
} /i,n75/y?
Lu}jk W*
%nZ:)J>kz
public String getSFileName() 9`*ST(0/
{ `D77CC]vU
return sFileName; 5pJe`}O4
} v#Rh:#7O%U
B%8@yS
=%m{|HQ`
public void setSFileName(String value) J#$U<`j*G
{ ^bv^&V&IB
sFileName = value; q-`&C
} SZKYq8ZA)V
~,}|~
Cy[G7A%
public int getNSplitter() p*b_"aF1
{ 9G/!18 X?f
return nSplitter; w0~%,S
} @R5^J{T
e\V -L_
2Xe1qzvo
public void setNSplitter(int nCount) BH0m[9nU;
{ 76tn`4NIP
nSplitter = nCount; eUy*0
} &[[r|
} Nm"P8/-09
NBPP?\1
!i"zM}
/* $9`#p/V
**Utility.java uHKEt[PS$
*/ *a Z1 4
package NetFox; 76!LMNf
:i<*~0r<
JdS,s5Z>
public class Utility { R;!,(l
!mxH/{+|n
GeP={lj
public Utility() hWy@?r.
{ qnp}#BZ
n<C] 6H
fmixWL7.Zg
} ?0; 2ct
TaRPMKk
//线程睡眠 VW\S>=O99
public static void sleep(int nSecond) tczJk1g}
{ bA)nWWSg=
try{ J1G}l5N
Thread.sleep(nSecond); 7W)W9=&BT
} TLsF c^X
catch(Exception e) |`o|;A]
{ bo|THS
e.printStackTrace (); LTe ({6l0
} 8{ZTHY-
} @/s|<*
5?^#v
//日志 r]!#v{#.
public static void log(String sMsg) k;^$Pd?t
{ z6R|1L 1
System.err.println(sMsg); p-iFe\+
} _{jC?rzb
Z^>4qf,k
(X "J)xaQ
public static void log(int sMsg) hP)Zm%@0f
{ C][$0
System.err.println(sMsg); fB+h( 2N~
} -~]H5er`
} Mc,|C)
O.+J%],
y$%oR6K7-
/* 7Y8~")f
**TestMethod.java <YW)8J
*/ Z{B e
package NetFox; W4o8]&A
fn,n'E]
\x-2qlZ
public class TestMethod { RHFRN&RU$
|<u+Xi ~
cANt7
public TestMethod() cTq@"v di
{ ///xx/weblogic60b2_win.exe 4G,FJjE`p
try{ 2 q4p-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9K@I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &\9%;k
SiteFileFetch fileFetch = new SiteFileFetch(bean); f- XUto
fileFetch.start(); &<;T$Y
} vqN/crJ@
catch(Exception e){e.printStackTrace ();} r,JQR)l0@V
/Z6lnm7wJ
B/;>v
} *V kaFQZ$,
M*0^<e~]F
q? ">
public static void main(String[] args) q5_zsUR=
{ :XhF:c[.:
new TestMethod(); Es+I]o0K
} (?Mn_FNE|
} =_`q;Tu=
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