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)); P^U.VXY}
} Vock19P
for(int i=0;i<nEndPos.length-1;i++) 7(P4KvkI
{ /;!I.|j
nEndPos = nStartPos[i+1]; Xn>>hzj-x?
} K$r)^K=s
nEndPos[nEndPos.length-1] = nFileLength; .YP&E1lNi
} @2hOy@V
} }9!}T~NMs
`)MKCw$e
q!~DCv df
//启动子线程 >;VZB/d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]Zc\si3i&
for(int i=0;i<nStartPos.length;i++) Vl>KeZ+
{ ~dP\0x0AB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #B#xSmak
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3\C+g{}e
nStartPos,nEndPos,i); 2!9Zw$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w@n}DCFt
fileSplitterFetch.start(); ] ;CJ6gM~
} <Z\{ijfvD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {wDe#c{_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <(yAat$H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q("4R
nEndPos = " + nFileLength); `O;4b#!g
// fileSplitterFetch[nPos.length-1].start(); @Pi]kWW})
3UKd=YsJ
Q}a(vlZ
//等待子线程结束 Z%=A[`5]
//int count = 0; 1KR4Wq@
//是否结束while循环 <(V~eo e
boolean breakWhile = false; kLpq{GUv:
lvNi/jk
$xF[j9nM
while(!bStop) _N>#/v)Yi
{ _+~&t9A!
write_nPos(); >hV2p/D
Utility.sleep(500); JZE@W-2
breakWhile = true; j%J>LeTca
;18u02z^
0"ooHP$1
for(int i=0;i<nStartPos.length;i++) Ww#!-,*]o
{ pF8+< T3y
if(!fileSplitterFetch.bDownOver) k2PK4Ua_}q
{ Z)@[N 6\?
breakWhile = false; >ffC?5+
break; L=M'QJl9
} U;"J8
} fL]jk1.Xv-
if(breakWhile) ]^i^L
break; whrDw1>(
BNFYUcVP
S_RP&+!7
//count++; 'fk6]&-I
//if(count>4) ?5,I`9
// siteStop(); Y>~jho
} {Ve`VV5E
pK"Z9y&
!@y/{~Gu
System.err.println("文件下载结束！"); OPogH=vf
} >l=^3B,j
catch(Exception e){e.printStackTrace ();} IY mkZ?cW
} HS\'{4P
G-;EB
?du*ITim
//获得文件长度 jpoNTl'
public long getFileSize() rls{~ZRl
{ f|)~_JH
int nFileLength = -1; vg_PMy\
try{ x\VP X
URL url = new URL(siteInfoBean.getSSiteURL()); 8s-X H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `0!%jz=
httpConnection.setRequestProperty("User-Agent","NetFox"); 4T v=sP
rq}xuSFI
}m7$,'C%P
int responseCode=httpConnection.getResponseCode(); `VDvxl@1
if(responseCode>=400) J(=y$8xje
{ (N)>?r@n`
processErrorCode(responseCode); _9Rj,
return -2; //-2 represent access is error R\/tKZJjb
} _5$L`&
#YK3Ogb,
d3#e7rQ8
String sHeader; {SRD\&J[
lQm7`+
8LXK3D}?3
for(int i=1;;i++) ?|!m
{ JRj{Q 1J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :hR^?{9Z4>
//Utility.log(in.readLine()); R|wS*xd,
sHeader=httpConnection.getHeaderFieldKey(i); xj3{Ke`6
if(sHeader!=null) FT J{
{ p1mAoVxR
if(sHeader.equals("Content-Length")) && PZ;
{ 7 `c!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); YNKvR
break; y|3("&)"S
} 'Z#>K*
} zG^$-L.n
else 4%JJ}{Ff
break; 5Nbq9YY
} =ReSlt
} u|D L?c>W
catch(IOException e){e.printStackTrace ();} _g,_G
catch(Exception e){e.printStackTrace ();} G-sQL'L[U
D*sL&Rt][Y
nHp$5|r<
Utility.log(nFileLength); XJ"xMv
'R42N3|F
zvdIwV&oT
return nFileLength; , E$f"
} Q]VG6x
i<=2 L?[.I
6KD-nr{S
//保存下载信息（文件指针位置） Z J1@z.
private void write_nPos() !:tr\L {
{ I#7H)^us
try{ <JvYCWX`
output = new DataOutputStream(new FileOutputStream(tmpFile)); cjd-B:l
output.writeInt(nStartPos.length); X;#Ni}af
for(int i=0;i<nStartPos.length;i++) 7-\wr^ll3
{ y>d`cRy
// output.writeLong(nPos); U!JmSP
output.writeLong(fileSplitterFetch.nStartPos); Xf mN/j2
output.writeLong(fileSplitterFetch.nEndPos); :lmimAMt
} =@X?$>'
output.close(); Y@T$O<*
} '0&HkM{ D
catch(IOException e){e.printStackTrace ();} W2M[w_~QE
catch(Exception e){e.printStackTrace ();} %dhrXK5
} P:1eWP
TB84}
QA)W(1
//读取保存的下载信息（文件指针位置） |8GLS4.]t
private void read_nPos() !0):g/2h
{ &+H\ST(/
try{ I'N!j>5oX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BuxU+
int nCount = input.readInt(); 'AmA3x)9u
nStartPos = new long[nCount]; y$6EEp
nEndPos = new long[nCount]; Y/pK
for(int i=0;i<nStartPos.length;i++) 1YU?+K
{ ~~I]SI k{
nStartPos = input.readLong(); AgUjC
nEndPos = input.readLong(); =GeGlI6
} z=8l@&hYLq
input.close(); n,_9Eh#WD
} yD8Qy+6L
catch(IOException e){e.printStackTrace ();} \{ C ~B;=
catch(Exception e){e.printStackTrace ();} <dz_7hR"
} `FX?P`\@I
PQz[IZ
O<dCvH
private void processErrorCode(int nErrorCode) 1W}k>t8?h'
{ k ,r*xt
System.err.println("Error Code : " + nErrorCode); st#^pWL
} r|/9'{!
qQ,(O5$|
dwiLu&]u
//停止文件下载 vVsaGW
public void siteStop() =eh!eZ9
{ k RSY;V
bStop = true; BV\~Dm]"
for(int i=0;i<nStartPos.length;i++) :X7O4?ww
fileSplitterFetch.splitterStop(); 2|`Mb~E;
s=z$;1C
n^l5M^.
} I+jc
} |O"Pb`V+
//负责部分文件的抓取 'gsO}xj
**FileSplitterFetch.java {e0aH `me
*/ !thFayq
package NetFox; Z0wH%o\
U2\k7I
H;Gs0Qi;
import java.io.*; Lu[Hz8
import java.net.*; v^[!NygShs
l SuNZYaO
oB'5':
public class FileSplitterFetch extends Thread { th0>u.hJ
>km$zfM2-
pNu?DF{ 3
String sURL; //File URL ,I,Zl.5
long nStartPos; //File Snippet Start Position [g+WL\1
long nEndPos; //File Snippet End Position =OKUSHu@V
int nThreadID; //Thread's ID L%pAEoSG
boolean bDownOver = false; //Downing is over 7&L8zl|K
boolean bStop = false; //Stop identical >Tn[CgH]7
FileAccessI fileAccessI = null; //File Access interface KQ(S\
'}F9f?
m]{/5L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^lK!tOeO
{ yC!>7@m
this.sURL = sURL; t!>0^['g4
this.nStartPos = nStart; +|4olK$[
this.nEndPos = nEnd; /~?[70B}E
nThreadID = id; {%\;'&@z\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Oj2=&uz
} Q H>g-@
";n%^I}
l[nf"'
public void run() 5\}QOL
{ 7CX5pRNL
while(nStartPos < nEndPos && !bStop) a@?ebCE
{ ma`sv<f4-!
_~*ba+{
7&V3f=aj6
try{ x3jjtjf
URL url = new URL(sURL); Dd$8{~h"G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); azTiY@/
httpConnection.setRequestProperty("User-Agent","NetFox"); ZMK1V)ohn
String sProperty = "bytes="+nStartPos+"-"; kkj_k:Eah
httpConnection.setRequestProperty("RANGE",sProperty); $u)#-X;x
Utility.log(sProperty); |Y2n6gkH[
bW3Ah?0N
q1|@v#kH6
InputStream input = httpConnection.getInputStream(); ;\T~Hc}&;
//logResponseHead(httpConnection); u(`7F(R
e.!~7c_z?
o+S?j*mv@
byte[] b = new byte[1024]; F5w=tK
int nRead; =[gFaB_H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V:gXP1P
{ c&`]O\D-c
nStartPos += fileAccessI.write(b,0,nRead); F-Ku0z]){?
//if(nThreadID == 1) eNm Wul
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KXu1%`x=%Z
} XhOg>
mt-t8~A
|%(qaPA1
Utility.log("Thread " + nThreadID + " is over!"); !~-@sq
bDownOver = true; ^)3=WD'!
//nPos = fileAccessI.write (b,0,nRead); ,^@/I:
} XKT[8o<L
catch(Exception e){e.printStackTrace ();} \@_?mL@=
} SMQC/t]HT
} $@WA}\D
n+Ng7
cZw_^@!
//打印回应的头信息 2d&HSW
public void logResponseHead(HttpURLConnection con) >R\!Qk
{ 6%&w\<(SG
for(int i=1;;i++) 8%b-.O:_$
{ #Jfmt~ks'
String header=con.getHeaderFieldKey(i); A5G@u}YS5
if(header!=null) )/bv@Am
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ek '%%%
Utility.log(header+" : "+con.getHeaderField(header)); \6/!{D,
else 4HGR-S/
break; RRGs:h@;
} krXU*64
} u>2opI~m
yJ8_<A
9}d^ll&
public void splitterStop() +1Rz+
{ e&9v`8}
bStop = true; Js9EsN%
} _wZr`E)
Wtflw>-
@^b>S6d"
} u4[rA2Bf8E
m!Aw,*m+*
=%;TVJk*a
/* }y%mG&KSz
**FileAccess.java XBTjb
*//文件访问(定位，写) _+&/P&
package NetFox; QEY#U|
import java.io.*; byIP]7Ld
{\ BFWGX
s>ZlW:jY
public class FileAccessI implements Serializable{ :)k|Onz
3+I"Dm,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,WS{O6O7
RandomAccessFile oSavedFile; l_T5KV
long nPos; "u"?~
tLGNYW!K
j<A; i
public FileAccessI() throws IOException +?0r%R%\
{ .gw6W0\F
this("",0); 8oP"?ew#
} x\5\KGw16
<T$rvS
}DkdF
public FileAccessI(String sName,long nPos) throws IOException fvoPV&:
{ H$)otDOE
oSavedFile = new RandomAccessFile(sName,"rw"); #2qv"ntW
this.nPos = nPos; 8fQXif\z
oSavedFile.seek(nPos); =o4McV}
} oX6()FR
i0[mU,
ezr'"1Ba}
public synchronized int write(byte[] b,int nStart,int nLen) >NBwtF>
{ 2| ERif;)
int n = -1; -p20UP 1I
try{ v <E#`4{
oSavedFile.write(b,nStart,nLen); V}q=!zz
n = nLen; ;QQ/bM&I
} sW@_q8lG
catch(IOException e) xGK"`\V
{ <{k8 K6
e.printStackTrace (); Xm^/t#
} o 0H.DeP
C.hRL4+;Zm
JE[J}-2
return n; X@@7Qk
} (.9H1aO46|
;VPYWss
ljk,R G
} >F;yfv;
PKt;]T0
+HY.m+T
/* 5Fa/Q>N
**SiteInfoBean.java -W)8Z.
*/ WL1$LLzN
package NetFox; V(6Ql j7
{o8K&XU#&t
!]!J"!xg*
public class SiteInfoBean { Qy|6A@
uS{WeL6%
c4FU@^Vv
private String sSiteURL; //Site's URL 8"J6(KS
private String sFilePath; //Saved File's Path v cb}Gk
private String sFileName; //Saved File's Name ~>5
private int nSplitter; //Count of Splited Downloading File AF"XsEt.e
W^1)70<y
8,?*eYNjb
public SiteInfoBean() Z(o]8*;Ai
{//nSplitter的缺省值为5 DM*u;t{i
//default value of nSplitter is 5 a |0f B4G
this("","","",5); \.{ZgL5"
} sm;\;MP*yH
5OHF=wh
X5o{d4R L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QPp>%iE@
{ m7,;Hr(
sSiteURL= sURL; C'fQ Z,r-v
sFilePath = sPath; DVjsz
sFileName = sName; _SQ0`=+
this.nSplitter = nSpiltter; X6EnC57
Mt(;7q@1c
87:V-*8
} 3>buZ6vh
4>te>[
NpF)|Ppb{
public String getSSiteURL() P<IZ%eS3B
{ 5t[7taLX\
return sSiteURL; ^ &VN=Y6z
} uE3xzF
p(x<h
3Cl&1K #5
public void setSSiteURL(String value) 420yaw/":
{ 3("E5lI(g:
sSiteURL = value; r[RO"Ej"
} U7d05y'
2B=+p83<
,:?=j80m
public String getSFilePath() jI,?*n<
{ %1%@L7wP>
return sFilePath; ]j^rJ|WTH
} OJPi*i5*
c:_dW;MJ0
;F\sMf{
public void setSFilePath(String value) >&uR=Yd
{ ? ]hS^&
sFilePath = value; (/3E,6gMk^
} 6yXMre)YV
Mg=R**s1x%
f&`yiy_
public String getSFileName() kDK0L3}nr]
{ $C9['GGR
return sFileName; VyxX5Lrj
} rb<9/z5-
dZ'H'm;,!
c"^g*i2&0
public void setSFileName(String value) xX2/uxi8
{ *Au[{sR
sFileName = value; #=aTSw X
} @!2vS@f
yo"!C?82=
XFWo"%}w
public int getNSplitter() mA0|W#NB
{ -3&mgd
return nSplitter; ,(&5y:o
} 4W36VtQ@E
I"r[4>>B>0
*aS[^iX?s
public void setNSplitter(int nCount) EMMp4KKOx+
{ CGJ>j}C
nSplitter = nCount; 3B[u2o>
} ;$rh&ET
} %3 VToj@`>
1agI/R
t Ai?Bjo
/* SoL"M[O
**Utility.java {xJ<)^fD8
*/ $o>6Io|D
package NetFox; Ls(l
udGZ%Mr_
qq[Enf|/y
public class Utility { Ai.^~#%X
Bz*6M
5u&hp
public Utility() "y$s`n4Mj
{ d m$iiRY
[rtMx8T
k|[86<&[
} 7G5VwO
8Xk,Nbcqt
//线程睡眠 qBXIR}
public static void sleep(int nSecond) yc3i> w`
{ @sLB _f
try{ K8g9IZ*lT
Thread.sleep(nSecond); ]:F?k#c
} \4roM1&[
catch(Exception e) z)XIA)i6
{ I<LIw8LI
e.printStackTrace (); $%0A#&DVh
} <+)B8I^
} J#*R]LU|
5qQ\H}
//日志 F@Cxjz
public static void log(String sMsg) "IKbb7x
{ C#D8 E.W
System.err.println(sMsg); anxwK47
} Lt\=E8&rh
OZi4S3k
K:8. Dvn
public static void log(int sMsg) `*HM5 1U
{ (`FY{]Wz!
System.err.println(sMsg); - {|
} &Y|AX2KUC
} /F7X"_(H
+U*:WKdI?
fD ?w!7f-1
/* Jw)-6WJ!uO
**TestMethod.java hxx`f-#=
*/ oiNt'HQ2/
package NetFox; dEG1[QG
TC^fyxq
T+~ _D
public class TestMethod { AN 'L- E
R?H[{AX
&(YNz9L
public TestMethod() 5Int,SX
{ ///xx/weblogic60b2_win.exe t6a$ZN;
try{ =Z}=nS?4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,1|0]:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !=rJ~s F/{
SiteFileFetch fileFetch = new SiteFileFetch(bean); x|q|> dPB
fileFetch.start(); T~b6Zu6
} #CTHCwYo
catch(Exception e){e.printStackTrace ();} e{7"7wn=
( t59SY
mVdg0
} p|o?nI
9Jj:d)E>o
d+158qQOh]
public static void main(String[] args) )w'GnUqWz
{ 31=vUS
new TestMethod(); _&|<(m&."
} BhCOT+i;c
} Y[Kpd[)[v
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