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)); ,y{0bq9*2
} _o&94&
for(int i=0;i<nEndPos.length-1;i++) {&0mK"z_
{ 6SV7\,2M
nEndPos = nStartPos[i+1]; k*OvcYL1A
} /=q.tDH=I
nEndPos[nEndPos.length-1] = nFileLength; F G3Sk!O6
} ,zD_% ox
} **.:)
h)^dB,~
-E}>h[;qZ
//启动子线程 au,jAk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8H7O/n
for(int i=0;i<nStartPos.length;i++) k)|'JDm
{ ZWFG?8lJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |G)Y8 #D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {v,{x1
nStartPos,nEndPos,i); yAAG2c4(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kq>GMUl~@
fileSplitterFetch.start(); ](_{,P
} ,TEuM|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @W#fui<<}Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LSSW.Oz2L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z;[gEA+I
nEndPos = " + nFileLength); L 43`^;u
// fileSplitterFetch[nPos.length-1].start(); Ut]2`8-
6zv;lx0<D&
amMjuyW
//等待子线程结束 GKiq0*/M
//int count = 0; {=s:P|ah
//是否结束while循环 "havi,m
boolean breakWhile = false; qFrt^+@
"/Om}*VhD
{K<uM'ww>
while(!bStop) {>wI8
{ m"<4\;GK
write_nPos(); 1B6C<cL:sU
Utility.sleep(500); 8~.iuFp
breakWhile = true; d3Y(SPO
.N/GfR`0/<
|O57N'/
for(int i=0;i<nStartPos.length;i++) /8=:qIJYA
{ m5)EQE}gPp
if(!fileSplitterFetch.bDownOver) xLe =d|6
{ E2Us#a
breakWhile = false; h (qshbC}
break; 0{-`Th+h
} #fwzFS \XL
} Ica3
if(breakWhile) 4sb )^3T
break; .F4oo=
=Na/3\^WP
{%=S+89l
//count++; D*CIE\+
//if(count>4) 3T"#T&eL
// siteStop(); HmhUc,EC
} qe[
VPWxHVf
aF,jJ}On
System.err.println("文件下载结束！"); 4g>1Gqv6
} jo<>Hc{g>
catch(Exception e){e.printStackTrace ();} `E{;85bDH
} anK[P'Y
~l(G6/R
_t$lcOT
//获得文件长度 $< A8gTJ
public long getFileSize() ftO+.-sm<
{ {-o7w0d_
int nFileLength = -1; 03~+-h&n
try{ ^uC"dfH
URL url = new URL(siteInfoBean.getSSiteURL()); CKx\V+\O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4Y`! bT`
httpConnection.setRequestProperty("User-Agent","NetFox"); EfFj!)fz
NR;q`Xe-
A *a{
int responseCode=httpConnection.getResponseCode(); Jz=;mrW
if(responseCode>=400) =*{K@p_
{ B"7$!Co
processErrorCode(responseCode); BHF{-z
return -2; //-2 represent access is error 2^cAK t6bC
} W8Ke1(ws&
^?E^']H)5u
'&RZ3@}+
String sHeader; `kqT{fs
d|>9rX+f
c zZrP"
for(int i=1;;i++) I h5/=_n
{ $|>6z_3%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ny278tr Q7
//Utility.log(in.readLine()); nwY2BIB
sHeader=httpConnection.getHeaderFieldKey(i); NnJ>0|74g
if(sHeader!=null) JCM)N8~i
{ UN,<6D3\b
if(sHeader.equals("Content-Length")) -;sJ25(
{ aw%>YrJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "CIpo/ebL
break; `DI{wqV9
} u86J.K1Q
} g ^D)x[
else ;~}-AI-
break; }9MW!Ss
} Z|]l"W*w
} UeMnc 5y
catch(IOException e){e.printStackTrace ();} #rh0r`
catch(Exception e){e.printStackTrace ();} '}wG"0
vs5 D:cZ}
{KW&wsI
Utility.log(nFileLength); EZ:I$X
V->.|[J
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return nFileLength; RH<@c^ S
} j)6@q@P/
/uy&2l
@#bBs9@gv
//保存下载信息（文件指针位置） [37f#p
private void write_nPos() VaD:
{ OwNAN
try{ L~^e\^sP
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1.hOE>A%
output.writeInt(nStartPos.length); +9<,3IJe6
for(int i=0;i<nStartPos.length;i++) 0-8ELX[#
{ $=\oJ-(!@S
// output.writeLong(nPos); @qg0u#k5
output.writeLong(fileSplitterFetch.nStartPos); ~0VwF
output.writeLong(fileSplitterFetch.nEndPos); I>N-95
} *D,v>(
output.close(); [,\'V0
} E&RoaY0
catch(IOException e){e.printStackTrace ();} [VfLv.8w
catch(Exception e){e.printStackTrace ();} *T.={>HE8
} rg#qSrHp
8r7/IGFg
|u?k-,uI9
//读取保存的下载信息（文件指针位置） Y}V)4j
private void read_nPos() !mw{T D
{ +~R.7NE%
try{ o`<h=+a\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H;7O\
int nCount = input.readInt(); S+` !%hJ
nStartPos = new long[nCount]; K9x*Sep
nEndPos = new long[nCount]; w\0Oz?N
for(int i=0;i<nStartPos.length;i++) *>}McvtTw
{ J ,Qy`Y B
nStartPos = input.readLong(); /t%"Dh8x
nEndPos = input.readLong(); /u" cl2|
} Q1N,^71
input.close(); a}^!TC>%1i
} 4aIlzaA
catch(IOException e){e.printStackTrace ();} |R_xY=z?
catch(Exception e){e.printStackTrace ();} Li?{e+g
} 6E*Zj1KX
Q%gY.n{=
~2, wI<Nz
private void processErrorCode(int nErrorCode) Og&0Z)%
{ SdEb[
System.err.println("Error Code : " + nErrorCode); L<[,7V
} [)b/uR
IkE'_F
o m{n"cg
//停止文件下载 0ER6cTo-t
public void siteStop() 7|{%CckN
{ a$+e8>
bStop = true; a9mr-`<
for(int i=0;i<nStartPos.length;i++) T }8r;<P6
fileSplitterFetch.splitterStop(); p ] $
W#JVUGYD
'|dKg"Yl
} &9jUf:gJ0
} 37ri b
//负责部分文件的抓取 8V53+]c$Y
**FileSplitterFetch.java skmDsZzw
*/ P /f ~
package NetFox; h!JjN$
E|8s2t
I'6ed`|
import java.io.*; \nWzn4f
import java.net.*; hg86#jq%
|Ls&~'ik
8WLh]MD`
public class FileSplitterFetch extends Thread { ^<5^9]x
'3Lx!pMhN
j*3sjOoC
String sURL; //File URL ( .6tz
long nStartPos; //File Snippet Start Position R- ?0k:
long nEndPos; //File Snippet End Position %_i0go,^
int nThreadID; //Thread's ID hQW#a]]V:
boolean bDownOver = false; //Downing is over x.yb4i=Jq
boolean bStop = false; //Stop identical Z"+rg9/p
FileAccessI fileAccessI = null; //File Access interface .DV#-tUh
R!M|k%(
&bOodkOb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +kdU%Sm
{ `5~o=g
this.sURL = sURL; 8Vg`;_-
this.nStartPos = nStart; OU Yb-
this.nEndPos = nEnd; ggYIq*4
nThreadID = id; T_;G))q'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DrVbx
} ,2:L{8_L
:ayO+fr#
H 29 _ /
public void run() ?M1 QJ
{ 4HYH\ey
while(nStartPos < nEndPos && !bStop) =tvm=
{ ,y{fqa4
iM-hWhU
hzf}_1
try{ , K"2tb
URL url = new URL(sURL); S)AE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \)6?u_(u
httpConnection.setRequestProperty("User-Agent","NetFox"); -%QEzu&
String sProperty = "bytes="+nStartPos+"-"; Wf&G9Be?8
httpConnection.setRequestProperty("RANGE",sProperty); fb S.
Utility.log(sProperty); Q:xI} ]FM
N[?4yV2s
B )3SiU
InputStream input = httpConnection.getInputStream(); ?;r7j V/`j
//logResponseHead(httpConnection); 4VL!U?dk
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a!6OE"?QQ
byte[] b = new byte[1024]; iz|9a|k6x
int nRead; *dn-,Q%`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8aM% 9OU
{ SUQ}^gn]
nStartPos += fileAccessI.write(b,0,nRead); Vm5P@RU$w;
//if(nThreadID == 1) Yhv`IV-s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rq|czQ
} oCru5F
$@ #G+QQ_
(^OC%pc
Utility.log("Thread " + nThreadID + " is over!"); 6T'43h. :
bDownOver = true; 3By>t!~Q
//nPos = fileAccessI.write (b,0,nRead); "9Fv!*<-W
} @0x.n\M_
catch(Exception e){e.printStackTrace ();} tGy%n[ \
} cqU/Y_%l'
} \=:g$_l
;U:o'9^9T
zYl+BM-j,6
//打印回应的头信息 +Y%I0.?&5
public void logResponseHead(HttpURLConnection con) ^`C*";8Q
{ &wWGZ~T
for(int i=1;;i++) I>(z)"1
{ b*%WAVt2T
String header=con.getHeaderFieldKey(i); iF2IR{h
if(header!=null) C@:N5},]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s_e#y{{C2
Utility.log(header+" : "+con.getHeaderField(header)); X]qp~:4G
else kO\&mL& qD
break; kTe<1^,m
} 'bqf?3W
} <8}9s9Nk
T)?@E/VaS
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public void splitterStop() <zWQ[^
{ Iw-6Z+ 94
bStop = true; %4g4 C#
} hD~/6bx
hCx#Heh
ViC76aJ
} E52:c]<'m
ZCq\Zk1O&
mgl' d
/* P_}_D{G
**FileAccess.java k/f_@8
*//文件访问(定位，写) m>m`aLrnb
package NetFox; +GEKg~/4e
import java.io.*; :<|fZa4!"
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,DsT:8
public class FileAccessI implements Serializable{ y"n~ET}e7
X!'Xx8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (Y?yGq/
RandomAccessFile oSavedFile; M)It(K8R
long nPos; 2FtEt+A+'
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D}=i tu
public FileAccessI() throws IOException C]@B~X1H^
{ cF6@.)
this("",0); (>% Vj
} )FiU1E
.Sth
%JU23c*
public FileAccessI(String sName,long nPos) throws IOException WxI]Fcb<
{ IQ`aDo-V
oSavedFile = new RandomAccessFile(sName,"rw"); m<;" 1<k
this.nPos = nPos; kxiyF$ 9
oSavedFile.seek(nPos); JQv ZTwSI
} '<jp.sZQ
?9M+fi
ojI"<Q~g
public synchronized int write(byte[] b,int nStart,int nLen) v*p)"J *
{ tz>X'L
int n = -1; 0{@Ovc
try{ M%LwC/h:,
oSavedFile.write(b,nStart,nLen); ^hTJp{
n = nLen; YXOD fd%L
} B#lj8I^|
catch(IOException e) DD3yl\#,
{ 0md{e`'q:
e.printStackTrace (); `o-<,
} .jU0Hu{F4
!,WRXE&j
n_gB#L$
return n; P =Gb
} zTzG&B-
Q9 ",
~|jy$*m4A
} .Zm }
aYX'&k `
?-p aM5Q+
/* "K=)J'/n
**SiteInfoBean.java bpCe&*\6K
*/ Z@Z`8M@Q,
package NetFox; ,S K6*tpI
) FsSXnZL
$G.|5sEk
public class SiteInfoBean { U9%nku4
/R?uxhV
:H k4i%hGk
private String sSiteURL; //Site's URL 2Nzcej
private String sFilePath; //Saved File's Path 1e%Xyqb
private String sFileName; //Saved File's Name 4&WzGnK
private int nSplitter; //Count of Splited Downloading File _Xe< JJvq
^W*)3;5
5.;$9~d
public SiteInfoBean() ]zAg6*-/B
{//nSplitter的缺省值为5 p#NZ\qJ
//default value of nSplitter is 5 ZSf+5{2m
this("","","",5); f4^_FK&
} `{;&Qcg6m
Y)5}bmL
uvd>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (S{c*"}2
{ k}7)pJNj
sSiteURL= sURL; 'v5gg2
sFilePath = sPath; 2)]*re)
sFileName = sName; [^P2Kn
this.nSplitter = nSpiltter; iIRigW
4H'&5
%^A++Z$`
} qa#F}aGd
^DJU99
T!$HVHh&,}
public String getSSiteURL() LZ$!=vg4
{ Qk?Jy<Ra
return sSiteURL; ,X):2_m
} < duM8
*Ux"3IXO
A>S2BL#=
public void setSSiteURL(String value) l0)6[yXK
{ ZmF32Ir
sSiteURL = value; J>|`
} =-Tetp
.v!e=i}.
z81!F'x;
public String getSFilePath() 3"RZiOyv
{ G(e?]{(
return sFilePath; g_=ZcGC
} <Z_`^~!
Cl=ExpX/O
~Y[b QuA=)
public void setSFilePath(String value) }x-8@9S~z
{ L@uKE jR
sFilePath = value; xEqrs6sR
} eZo%q,L
ObnB6ShKi
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public String getSFileName() M3;B]iRQD
{ /GNYv*
return sFileName; T9yW# .
} X[}%iEWzT
C5?M/xj
m5*RB1
public void setSFileName(String value) ~CscctD{;
{ L"0L_G
sFileName = value; j/\XeG>
} -0Ek&"=Z^
)i>KgX
9IMcp~zX
public int getNSplitter() 8X5XwFf}
{ 7v_e"[s~
return nSplitter; V2X(f6v
} Uyh#g^r
{I ,'
Q)/q h;Ru
public void setNSplitter(int nCount) <R$|J|
{ .N2Yxty8>
nSplitter = nCount; cE[lB08
} |SmN.*&(9
} PE>_;k-@k
O1"!'Gk[!L
|9h[Q[m
/* $Z4p$o dk
**Utility.java i`X{pEKP+
*/ N C&1l]
package NetFox; Fk\xq`3'c
"Q( 8FF
B5hGzplS
public class Utility { >JhQ=j
L[^e<I
U+z&jdnhDR
public Utility() D{mu2'q
{ D+U^ pl-
3 V<8
?w+T_EH
} a)e2WgVB/E
&fcRVku
//线程睡眠 20qT1!ju
public static void sleep(int nSecond) z{ 8!3>:E
{ oUqNA|l T
try{ '#fj)
Thread.sleep(nSecond); RK,~mXA
} 4d#W[
catch(Exception e) *QLbrR
{ q^s$4q
e.printStackTrace (); Ugn"w E
} nsPM`dz/
} {_Y\Y&#
:2?du
//日志 c~V\,lcI
public static void log(String sMsg) ??F{Gli"C`
{ #KIHq2:.4
System.err.println(sMsg); `c icjA@~
} B\6\QQ;rUo
hE;
pJmn;XbME
public static void log(int sMsg) \%)p7PNY
{ 5o,82Kti
System.err.println(sMsg); sG3%~
} {MHr]A}X\
} )9*WmFc+#
*]LM2J
NH{0KZ R
/* uJ[dO}
**TestMethod.java 4x:fOhtP
*/ @c/~qP4
package NetFox; iZ{D_uxq
d-Sm<XHu.
TPrwC~\B/
public class TestMethod { ]!/1qF
%bAv.'C
,QK>e;:Be
public TestMethod() n7S[ F3
{ ///xx/weblogic60b2_win.exe 3V-pLs|
try{ n@*NQ`(_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }{[F+|\>,e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P%1s6fjU
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5n_<)Ycj
fileFetch.start(); :S.0e
} L"IdD5`7T
catch(Exception e){e.printStackTrace ();} rn(T Z}
[u<1DR
?xy~N?N
} Q@2Smtu~c
!a /
O:1YG$uKa
public static void main(String[] args) B"G;"X
{ k'm!|
new TestMethod(); HxkhlNB
} spJB6n(
} ;lP)
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