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)); F ;2w1S^
} cj'}4(
for(int i=0;i<nEndPos.length-1;i++) o_^?n[4
{ `I,,C,{C
nEndPos = nStartPos[i+1]; A*/HjTX
} O2%?
nEndPos[nEndPos.length-1] = nFileLength; De(Hw& IV
} b7p@Dn?E
} aD$v2)RR
k+ty>bP=
D,k"PaLP
//启动子线程 = < oBgD0k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RpD=]y!5_
for(int i=0;i<nStartPos.length;i++) T"DlT/\
{ >)M`IU[d^.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T, )__h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 428>BQA
nStartPos,nEndPos,i); |='z{WS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qh'ATo
fileSplitterFetch.start(); 1NgCw\
} M 4?ig}kh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W)f/0QX}W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @3C>BLI8+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2-Ej4I~
nEndPos = " + nFileLength); VYk!k3qS
// fileSplitterFetch[nPos.length-1].start(); zIu E9l
7B\Vs-d
< F.hZGss7
//等待子线程结束 3GhRWB-U
//int count = 0; !~rY1T~
//是否结束while循环 j+uLV{~g6
boolean breakWhile = false; P<a)25be/
9E"vN
O%5 r[
while(!bStop) [VsKa\9u
{ HTS%^<u
write_nPos(); E4~<V=2l
Utility.sleep(500); \(^nSy&N
breakWhile = true; 5a|w+HO,
8)10o,#L
rFj-kojg
for(int i=0;i<nStartPos.length;i++) ,l:ORoND
{ t7j);W%e6
if(!fileSplitterFetch.bDownOver) +oovx2r&
{ #x 177I\
breakWhile = false; ASk|A!
break; |n,<1QY
} iA'lon
} 8L:ji,"
if(breakWhile) -v]Sr33L
break; noml8o
HiR[(5vnf
hM6PP7XH
//count++; vnM@QfN
//if(count>4) rPLm5ni
// siteStop(); q#,f 4P
} 7G}2,ueI
; Q3n
'kL#]
System.err.println("文件下载结束！"); rMLp-aR'
} $JMXV
catch(Exception e){e.printStackTrace ();} 5#+^E{
} !y@NAa0
C(#u[8
%}Ss,XJ
//获得文件长度 0;AA/
public long getFileSize() ?&63#B,iZ
{ 0Tx{3#
int nFileLength = -1; CzRc%%BA
try{ XF;ES3 d
URL url = new URL(siteInfoBean.getSSiteURL()); Of[XKFn_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d9;g]uj`
httpConnection.setRequestProperty("User-Agent","NetFox"); _lGdUt 2
o:3dfO%nuM
iB%gPoDCL@
int responseCode=httpConnection.getResponseCode(); }dWq=)*
if(responseCode>=400) o7sT=x9
{ ToXki,
processErrorCode(responseCode); DVB{2~7 4
return -2; //-2 represent access is error +'I+o5*
} W;'!gpa
Rn9m]x
,!Z*5
String sHeader; ]+XYEv
2.l Z:VLN
jB$IyQ;@
for(int i=1;;i++) J;{N72
{ 4W#vP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G MX?
//Utility.log(in.readLine()); &]v4@%<J
sHeader=httpConnection.getHeaderFieldKey(i); W&&;:Fr
if(sHeader!=null) Nn~~!q
{ :D%"EJ
if(sHeader.equals("Content-Length")) C)@y5. G;
{ G~2jUyv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 52 fA/sx
break; w$z}r
} -QM: q
} rV R1wsaL
else :Q $K<)[
break; )Ch2E|C?=8
} njScz"L~
} >L;eO'D
catch(IOException e){e.printStackTrace ();} 0=* 8
catch(Exception e){e.printStackTrace ();} Bm.:^:&k
aE&,]'6
E:JJ3X|
Utility.log(nFileLength); K?B{rE Lp
hbzC#@q
;V*R*R
return nFileLength; \>:CvTzF
} Z&1T
dJ2Hr;Lc
R?~Yp?B^
//保存下载信息（文件指针位置） 7n8~K3~;
private void write_nPos() ?Z Rs\+{vG
{ /'].lp
try{ ~$:|VHl
output = new DataOutputStream(new FileOutputStream(tmpFile)); bJRN;g
output.writeInt(nStartPos.length); lef2X1w}!
for(int i=0;i<nStartPos.length;i++) 5R@
{ Cjqklb/
// output.writeLong(nPos); {QHVo#
output.writeLong(fileSplitterFetch.nStartPos); HJXT9;w
output.writeLong(fileSplitterFetch.nEndPos); y#Fv+`YDl
} 6x h:/j3
output.close(); WG6FQAo^8
} J pFfzb
catch(IOException e){e.printStackTrace ();} {QcLu"?c
catch(Exception e){e.printStackTrace ();} 0fF(Z0R,
} WHsgjvh"
hd>aZ"nm1
#MX'^RZ>2
//读取保存的下载信息（文件指针位置） ,k{#S?:b
private void read_nPos() ohFJZ'
{ d F9!G;V
try{ 8YZbP5'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GN ]cDik
int nCount = input.readInt(); ud xZ0
nStartPos = new long[nCount]; #33fGmd[
nEndPos = new long[nCount]; ?ooe'V@
for(int i=0;i<nStartPos.length;i++) yaah*1ip[
{ 7ePqmB<.
nStartPos = input.readLong(); @ zs'Y8
nEndPos = input.readLong(); LQ(yScA@
} *AoR==:ya
input.close(); X%Z{K-
} P|.]DJ
catch(IOException e){e.printStackTrace ();} LQtj~c>X-|
catch(Exception e){e.printStackTrace ();} uJFdbBDSh
} g .onTFwN
biSz?DJ>
KNS.Nw7
private void processErrorCode(int nErrorCode) ~%^ tB
{ (8Bk;bd
System.err.println("Error Code : " + nErrorCode); (@%gS[]
} .q%WuQw
giZP.C"0
Y' %^NP}o
//停止文件下载 )Y2{_ bx4"
public void siteStop() zA$k0p
{ v%"|WV[N
bStop = true; Sz^ veh?
for(int i=0;i<nStartPos.length;i++) f0X_fm_q
fileSplitterFetch.splitterStop(); `8^TTQ
`S6x<J&T\/
.2%zC & ;
} 5]n[]FW
} 99:C"`E{
//负责部分文件的抓取 G]+&!4
**FileSplitterFetch.java .WPV dwV4U
*/ k\WR ]
package NetFox; |/09<F:L[
J3n-`k8
RLbKD>
import java.io.*; X:6c}p%,!
import java.net.*; I_<I&{N>
_59huC.
Ag&0wN+jTM
public class FileSplitterFetch extends Thread { 8g&? Cc
+pR[U4$
W7U2MqQ
String sURL; //File URL tS|(K=$
long nStartPos; //File Snippet Start Position kL$!E9
long nEndPos; //File Snippet End Position 'R c,Mq'
int nThreadID; //Thread's ID >N]7IU[-
boolean bDownOver = false; //Downing is over K Pt5=a
boolean bStop = false; //Stop identical pgOQIzu
FileAccessI fileAccessI = null; //File Access interface i(iXD
nHm}zOLc
c )G3k/T5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5<UVD:~z
{ yls ^cyX
this.sURL = sURL; kg'o&^/=
this.nStartPos = nStart; -?mfE+kt
this.nEndPos = nEnd; cUvz2TK
nThreadID = id; #)C[5?{SNq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #wV8X`g
} EJsM(iG]~M
;~D)~=|ZZ
VzY8rI
public void run() K2J\awX
{ `[W[H(AjQ
while(nStartPos < nEndPos && !bStop) LN@F+CyDc
{ 1IZ3=6
XDFx.)t
fp+gyTnd3
try{ y#q?A,C@n
URL url = new URL(sURL); T~Gvp0r}h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MM(xk
httpConnection.setRequestProperty("User-Agent","NetFox"); {&\jW!&n
String sProperty = "bytes="+nStartPos+"-"; kzt(i Y_6
httpConnection.setRequestProperty("RANGE",sProperty); `NgAT 3zq
Utility.log(sProperty); vTJ}8
hM{{\yZS
:TJv=T'p'
InputStream input = httpConnection.getInputStream(); Jo@|"cE=
//logResponseHead(httpConnection); R}q>O5O
?XA2&
oxz OA
byte[] b = new byte[1024]; cd$m25CxC
int nRead; "4uS3h2r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z7Q?D^miy
{ TWQG591
nStartPos += fileAccessI.write(b,0,nRead); (Q.waI
//if(nThreadID == 1) P!+'1KR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M#As0~y
} bO'Sgc[]
Q\ U:~g3
9983aFam
Utility.log("Thread " + nThreadID + " is over!"); :=wTvz
bDownOver = true; )u/yF*:n
//nPos = fileAccessI.write (b,0,nRead); (^u1~1E 5
} Qj.l:9%
catch(Exception e){e.printStackTrace ();} 1n:8s'\
} C4~;yhz
} d5D$&5Ec
gG-BVl"59
9Hc$G{[a
//打印回应的头信息 dt`{!lts'
public void logResponseHead(HttpURLConnection con) [&&1j@LQ*
{ ReM=eS
for(int i=1;;i++) pO ml8SQf
{ nij!1z|M
String header=con.getHeaderFieldKey(i); v(EEG/~
if(header!=null) 5ZMR,SZhC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1DvR[Lx%
Utility.log(header+" : "+con.getHeaderField(header)); -lhLA`6_R
else lJE93rXU
break; N1|$$9G+
} =y/8^^
} XI22+@d6
3WUTI(
K)\M5id]
public void splitterStop() Fl1;;F
{ 't6V:X
bStop = true; 1$%V{4bJ
} >]W)'lnO
Er+nk`UR_
2U; t(,dn'
} /ew Ukc8,
v7DE
unBy&?&p
/* D?0zhU
**FileAccess.java D,g1<:<
*//文件访问(定位，写) <j5NFJ9
package NetFox; wAxrc+
import java.io.*; e(I=^#u6
,;(PwJe
;uW}`Q<
public class FileAccessI implements Serializable{ >&p0d0
86\S?=J-b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IjR'Qou5
RandomAccessFile oSavedFile; opJMS6%r
long nPos; -tyK~aasQ
mGGsB5#w>
iTV) NsC}
public FileAccessI() throws IOException OBP1B@|l$+
{ 9$|Gfyv
this("",0); tX"Th'Qi
} *0>mB
e`v`XSA[p
d\FJFMW*9
public FileAccessI(String sName,long nPos) throws IOException `zE}1M%y
{ Ko/ I#)
oSavedFile = new RandomAccessFile(sName,"rw"); ^4`Px/&
this.nPos = nPos; &ZX{R#[L
oSavedFile.seek(nPos); vMs$ceq
} S-'fS2
LbZ:&/t^y8
n Ml%'[u
public synchronized int write(byte[] b,int nStart,int nLen) qg}O/K
{ }GZ}Q5
int n = -1; @;H,gEH^
try{ SY^dWLf
oSavedFile.write(b,nStart,nLen); Iz{R}#8CZ
n = nLen; P b]3&!a
} yT#{UA^
catch(IOException e) -M1YE
{ {!K-E9_,S
e.printStackTrace (); x"CZ]p&m
} NSFs\a@1
.LuB\o$
B-T/V-c7
return n; yin'vgQ
} ,s_T pq
]+m/;&0
)5.C]4jol
} C>[fB|^
8B#GbS K
RJON90,J
/* !Y:0c#MPH
**SiteInfoBean.java =Mb1o[
*/ h#hxOVl%x
package NetFox; @5[kcU>
&V<W>Y>|l*
vc]cNz:mQ
public class SiteInfoBean { \AC|?/sH
E3*\ ^Q_
F5 ]C{
private String sSiteURL; //Site's URL CY& hIh~S@
private String sFilePath; //Saved File's Path <uc1D/~^:
private String sFileName; //Saved File's Name vi)%$~
private int nSplitter; //Count of Splited Downloading File )Y8",Ig
gn{=%`[
atW'
public SiteInfoBean() QERU5|.wc
{//nSplitter的缺省值为5 _HA$ j2
//default value of nSplitter is 5 NKmoG\*
this("","","",5); `+/H^
} 5c;h&
}rdIUlVO\
er.CDKD%L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) & ``d
{ 7 ua6l[c
sSiteURL= sURL; m"9XT)N
sFilePath = sPath; O`$#Pg
sFileName = sName; AC.A'|"]i
this.nSplitter = nSpiltter; G8IY#
1'4J[S\cM
M@thI%lR
} \Yoa:|%*y
=9LC<2
Kwhdu<6
public String getSSiteURL() z1!6%W_.
{ pU!o7>p
return sSiteURL; oR*=|B
} Oc&),ru2l
4{qB X?
mga6[E<
public void setSSiteURL(String value) %o}(sShS
{ GyC/_ntn
sSiteURL = value; cW``M.d'F
} [ "xn5lE
/i)Hb`(S
)n=ARDd^e
public String getSFilePath() jvVi%k
{ g8'DoHJ*
return sFilePath; ^I]{7$6^
} I|/'Ds:
5v^L9!`@%v
= c~I .
public void setSFilePath(String value) 2>\\@1
{ PzY)"]g
sFilePath = value; 'xFYUU]#T^
} IwpbfZ
T[Pa/j{
\O7J=6fn
public String getSFileName() dZGbC9
{ L<(VG{)Z
return sFileName; 5% nt0dc
} mo1 puU
&2EBk=X
4%*hGh=
public void setSFileName(String value) cbKL$|
{ ["3df>!f
sFileName = value; &B!%fd.'
} Q1>zg,r
%d: A`7x
LEh)g[
public int getNSplitter() -cNx1et
{ AV@\ +0
return nSplitter; !;>(ie\
} l9{#sas
#1$}S=8*f
;^l_i4A
public void setNSplitter(int nCount) ;Mj002.\G
{ -O&"|
nSplitter = nCount; DM3B]Yl
} !v!N>f4S$
} b2h":G|s
|0{ i9.=
M@?"t_e1
/* NMjnL&P`
**Utility.java >,h1N$A+
*/ =sQ(iso%f
package NetFox; L(WOet('
%OI4a5V*l
A|<;
public class Utility { GYgWf1$8_D
eX<K5K.B
p[YWSjf
public Utility() Wp*sPZ
{ Um ;kd&#x
J0Four#MD
bNvAyKc-
} B5Va%?Wg?H
Riql,g/
//线程睡眠 @ t@|q
public static void sleep(int nSecond) Zd>ZY,-5
{ Ea`OT+#h(*
try{ |t\KsW
Thread.sleep(nSecond); Pi%tsKk%
} ida*]+ ~
catch(Exception e) 8Nvr93T,
{ 3%NE/lw1
e.printStackTrace (); v_-ls"l
} ChIoR:y>
} Am7| /
}'jV/
//日志 3@X|Gs'_S
public static void log(String sMsg) x_ySf!ih
{ Z90Fcp:R
System.err.println(sMsg); sM9-0A
} u'@Ely
OQ|,-
gY\mXM*^
public static void log(int sMsg) "4[<]pq
{ /$OIlu
System.err.println(sMsg); ~}%&p& p
} J_/05(48
} ZW2s[p r
Ko-QR(
3dU#Ueu
/* ]84YvpfW
**TestMethod.java mE_iS?1
*/ a?\ `
package NetFox; F$C+R&V_
9>zDJx
&0h=4i=6r
public class TestMethod { +ks$UvtY
=KW|#]RB^
Q}ZBr^*]1e
public TestMethod() ^X(_zinN"
{ ///xx/weblogic60b2_win.exe =~;zVP
try{ sK[Nti0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SFOQM*H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fX$6;Ae
SiteFileFetch fileFetch = new SiteFileFetch(bean); u4xA'X'~R
fileFetch.start(); KD9Ca $-
} @+Pf[J41
catch(Exception e){e.printStackTrace ();} X[Y#+z4
hAYQ6g$A
_]Z$YM
} np&HEh 6
SaTEZ.
Zm5nLxM
public static void main(String[] args) 2@4MC`&
{ 2voNgY
new TestMethod(); Ubpg92
} vatx+)
} Vc{/o=1u
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