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)); NF\^'W@N
} UE`4$^qs
for(int i=0;i<nEndPos.length-1;i++) $*)(8Cl
{ 10I`AjF0
nEndPos = nStartPos[i+1]; U;Y}2
} aj'8;E+
nEndPos[nEndPos.length-1] = nFileLength; rIWN!@.J
} h`;F<PFW
} yJ`1},^
|9"^s x
=|V]8 tN
//启动子线程 Rb}&c)4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^`r|3c0
for(int i=0;i<nStartPos.length;i++) [BR}4(7
{ H[!Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f, j(uP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u-M$45vct
nStartPos,nEndPos,i); rKs WS~U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?O>JtEz~lQ
fileSplitterFetch.start(); L\?g/l+k
} W;g+R-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), . N} }cJq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @NwM+^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f{5|}PL
nEndPos = " + nFileLength); SU}oKii /
// fileSplitterFetch[nPos.length-1].start(); AXv;r<
iGeT^!N
W!0
//等待子线程结束 3)Awj++
//int count = 0; ,<j5i?
//是否结束while循环 I;.E}k
boolean breakWhile = false; Q2pboZ86
EC!Cv;'
k|c0tvp
while(!bStop) 78inh%
{ eh7r'DmAR
write_nPos(); nMdN$E
Utility.sleep(500); ^5 =E`q".
breakWhile = true; }xlmsOHuI
D6!+
;OCI.S8
for(int i=0;i<nStartPos.length;i++) Odjd`DD1
{ M"l rwun^
if(!fileSplitterFetch.bDownOver) oUKbzr/C
{ F`V[G(f+r
breakWhile = false; qg:I+"u
break; Rf0\CEc
} JEF7hJz~
} ${6'
if(breakWhile) gw"l&r
break; =RE_Urt:
c7Qa !w
~Q9)Q
//count++; A*U'SCg(G
//if(count>4) =X5&au o
// siteStop(); &vvx"
} 7^TXlWn^G
BW-P%:B1!R
D!T4k]^
System.err.println("文件下载结束！"); $M<4Bqr
} WHLKf
catch(Exception e){e.printStackTrace ();} gN'i+mQcu
} m7eIhmP
$D\l%y/C
~#km0<r?
//获得文件长度 :.<TWBoV
public long getFileSize() *vE C,)
{ TY[d%rMm
int nFileLength = -1; GJ_)Cl+5E
try{ ~@?-|xLqQ
URL url = new URL(siteInfoBean.getSSiteURL()); n)!_HNc9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mXM>6>;y
httpConnection.setRequestProperty("User-Agent","NetFox"); j/mp.'P1k
+Q]'kJ<s
ugPI1'f
int responseCode=httpConnection.getResponseCode(); tskODM0Zf
if(responseCode>=400) &b")`p&K
{ VEKITBs
processErrorCode(responseCode); :k/U7 2
return -2; //-2 represent access is error ftuQ"Ds
} 6|qvo+%
Y4!q 1]TGX
`'.x*MNF
String sHeader; gH55caF<
'J0s%m|j
hg=G//
for(int i=1;;i++) w$:)wyR-
{ =usDI<3r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _`[6jhNa!
//Utility.log(in.readLine()); |&']ms5J
sHeader=httpConnection.getHeaderFieldKey(i); )t|Q7$v1
if(sHeader!=null) !Jnw_)
{ X0QS/S-+
if(sHeader.equals("Content-Length")) }lpm Hvs
{ 2Wf qgR[3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,[1`'nN@g
break; koY8=lh/
} <+,0G`
} VCRv(Ek
else B^Mtj5Oc
break; :!!`!*!JH
} CyDf[C)=
} lfeWtzOf
catch(IOException e){e.printStackTrace ();} 4EbiCSo
catch(Exception e){e.printStackTrace ();} ^Es)?>eah
:I(gz~u6
)nxIxr0d-
Utility.log(nFileLength); kzpbs?<;
ts!aKx
<qY>d,+E'
return nFileLength; EXzNehO~e
} [IA==B7
:FpBz~!a
L([>yQZ
//保存下载信息（文件指针位置） =,G(1#
private void write_nPos() ;-^9j)31+F
{ >F_Ne)}qTQ
try{ 6mpUk.M"
output = new DataOutputStream(new FileOutputStream(tmpFile)); $%8n,FJ[
output.writeInt(nStartPos.length); yOzKux8kB
for(int i=0;i<nStartPos.length;i++) Ao0PFY
{ E9-'!I!
// output.writeLong(nPos); 3g:+p
output.writeLong(fileSplitterFetch.nStartPos); <r3n?w8
output.writeLong(fileSplitterFetch.nEndPos); x99 Oq!
} ^V]DY!@k3_
output.close(); k T>}(G||
} :E`l(sI7J}
catch(IOException e){e.printStackTrace ();} F|{?GV%hF
catch(Exception e){e.printStackTrace ();} 5B/\vLHg4
} FY*0gp
Jo+C!kc
bl-s0Ax-
//读取保存的下载信息（文件指针位置） jk}PucV
private void read_nPos() GFkte
{ c&(,
try{ oe"ShhT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4\es@2q
int nCount = input.readInt(); S`@*zQ
nStartPos = new long[nCount]; :]hfmWC
nEndPos = new long[nCount]; $Ws2g*i
for(int i=0;i<nStartPos.length;i++) %'O(Y{$Y.
{ B*N8:u
nStartPos = input.readLong(); lf#six
nEndPos = input.readLong(); ]+9:i!s
} U5 "v1"Ec
input.close(); !Sh5o'D28
} 0N_Da N
catch(IOException e){e.printStackTrace ();} HbVm O]#$D
catch(Exception e){e.printStackTrace ();} OXV@LYP@
} TY?io@
Ve) :I
(@ sKE
private void processErrorCode(int nErrorCode) n\9*B##
{ S-|$sV^cG
System.err.println("Error Code : " + nErrorCode); Ooy96M~_G
} <sOB j'
<P-r)=^
K\Q 1/})
//停止文件下载 ohk =7d.'
public void siteStop() f`J"A:
{ ,DLNI0uV
bStop = true; ')RK(I
for(int i=0;i<nStartPos.length;i++) 8, ^UQ5x
fileSplitterFetch.splitterStop(); 7IH{5o\e
q[K)bg{HB
m:CpDxzbf
} SUhP e+
} m#'9)%t!J
//负责部分文件的抓取 A79SAheX#
**FileSplitterFetch.java -E"o)1Pj6C
*/ c[q3O**
package NetFox; WLH2B1_):
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e~dU "
import java.io.*; 0g4cyK~n]
import java.net.*; W>Kn*Dy8~
(qdk &
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public class FileSplitterFetch extends Thread { :+$_(*Z
4R6 .GO
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String sURL; //File URL OYy8u{@U:
long nStartPos; //File Snippet Start Position 9,+LNZ'k
long nEndPos; //File Snippet End Position m%puD9
int nThreadID; //Thread's ID 6m&I_icM
boolean bDownOver = false; //Downing is over J(60eTwQ
boolean bStop = false; //Stop identical (fS4qz:&l
FileAccessI fileAccessI = null; //File Access interface v<4zcMv
4r$t}t gX
n2~rrQ \/p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UqbE
{ %+}\i'j7
this.sURL = sURL; -xlI'gNg7
this.nStartPos = nStart; 9'M({/7y
this.nEndPos = nEnd; >EjBknl
nThreadID = id; b-XBs7OAx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FliN@RNo
} bfgLU.1I
;$]R#1i44
WxdYvmp6z[
public void run() a*`J]{3G
{ $[e*0!e
while(nStartPos < nEndPos && !bStop) M Cz3RZK
{ k9 E?5
O"GzeEY7
8~7EWl
try{ X.Kxio $o
URL url = new URL(sURL); Lm/^ 8V+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h/ic-iH(>
httpConnection.setRequestProperty("User-Agent","NetFox"); IU/*YI%W
String sProperty = "bytes="+nStartPos+"-"; NDi@x"];
httpConnection.setRequestProperty("RANGE",sProperty); S5vJC-"
Utility.log(sProperty); mc$dR, H0
3%k+<ho(
N?p$-{
InputStream input = httpConnection.getInputStream(); -xXM/3g1u
//logResponseHead(httpConnection); h2y@xnn
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;|c,
byte[] b = new byte[1024]; ):\L#>:w
int nRead; 42~;/4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hLF@'ln
{ F6Ixu_s
nStartPos += fileAccessI.write(b,0,nRead); .u)YZN0\
//if(nThreadID == 1) R?k1)n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <e"2<qVi
} %3cBhv[q4
gi8kYHldH
<W1!n$V ]
Utility.log("Thread " + nThreadID + " is over!"); hH~Z hB
bDownOver = true; 7)YU ;
//nPos = fileAccessI.write (b,0,nRead); quR':=S5f
} ;a|A1DmZ
catch(Exception e){e.printStackTrace ();} -95`.o
} 3e"G.0vJ
} f7L|Jc
RV~w+%f
w t}a`hxu
//打印回应的头信息 uAJC Q)@
public void logResponseHead(HttpURLConnection con) %u#pl=k}
{ [69aTl>/
for(int i=1;;i++) 2ZnTT{]_m
{ }x+{=%~N
String header=con.getHeaderFieldKey(i); &Jj?C
if(header!=null) &p*N8S8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cB TMuDT_
Utility.log(header+" : "+con.getHeaderField(header)); p 7sYgz
else r\yj$Gu>(
break; )pJzw-m"
} ?tOzhrv
} ;2$^=:8
WWY9U
F4@h}T5)
public void splitterStop() ][9M_.
{ G[jCmkK
bStop = true; hFKYRZtP.8
} $`i&\O2*
@$aCUJ/mE
IV\@GM:ait
} s)>]'ii
}b44^iL$9y
tNtP+v-{
/* X|b~,X%N
**FileAccess.java 'tOo0Zgc
*//文件访问(定位，写) Pai{?<zGi
package NetFox; VF4F7'
import java.io.*; ks! G \<I
tTY(I1
7XZ!UC;i
public class FileAccessI implements Serializable{ PR Y)hb;1
|_-FQ~Hf F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [scPs,5Y
RandomAccessFile oSavedFile; ,Ti#g8j
long nPos; .NabK
U7Ps2~x3
\KG{ 11
public FileAccessI() throws IOException z19y>j
{ +* &!u=%G
this("",0); \2T@]!n
} X(/W|RY{@
>kd2GZe^_J
FG'1;x!
public FileAccessI(String sName,long nPos) throws IOException Ek84yme#
{ W}KtB1J
oSavedFile = new RandomAccessFile(sName,"rw"); .n"aQ@!
this.nPos = nPos; gB?#T
oSavedFile.seek(nPos); G.9?ApG9
} @]~\H-8
"#JRw
#T+%$q [:
public synchronized int write(byte[] b,int nStart,int nLen) iNha<iS+
{ .@R{T3=Q
int n = -1; $g*|h G/{
try{ xl s_g/Q
oSavedFile.write(b,nStart,nLen); R#gip
n = nLen; )wAqaG_d
} x3]es"4Q
catch(IOException e) aRR*<dY
{ -\LB>\;qn
e.printStackTrace (); ~v2_vEu}JX
} D=e&"V a
TfMuQi'>
ZNzye1JSm
return n; Wh"oL;O
} !\CoJ.5=
^;N+"oq!y
e1K,4Bq
} 8JGt|,
"GgK,d}%
$/6.4"j
/* n pBpYtG
**SiteInfoBean.java dqnxhN+&
*/ S=2-<R
package NetFox; fk9FR^u
9"oc.ue.2D
Wl}d6ZTm
public class SiteInfoBean { ~c+0SuJ
J v'$6[?
z6$W@-Vd
private String sSiteURL; //Site's URL [|e7oNT(Q
private String sFilePath; //Saved File's Path {p+7QlgK
private String sFileName; //Saved File's Name Lylw('zZ
private int nSplitter; //Count of Splited Downloading File C;M.dd
?HttqK)
JZ'`.yK:
public SiteInfoBean() MJb!+E+
{//nSplitter的缺省值为5 Uk5jZ|
//default value of nSplitter is 5 )9,9yd~SI
this("","","",5); GAV|x]R
} /`3<@{D
j$a,93P5
[P407Sa"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6I"Q9(
{ |lrLTI^a
sSiteURL= sURL; B<x)^[<v
sFilePath = sPath; k~h'`(
sFileName = sName; A2!7a}*1(
this.nSplitter = nSpiltter; \-gZ_>)
1W;q(#q
Z25^+)uf*U
} pS;jrq I#
j-ZKEA{:1
I HgYgn
public String getSSiteURL() 5Jlz$]f
{ tUH#%
return sSiteURL; Y]Td+Zi
} +2!F6"hP
Tt<Ry'Z$3
:VX?j3qW
public void setSSiteURL(String value) QD-#sU]
{ ({87311%
sSiteURL = value; weYP^>gH'
} aPWlV= oG
_py%L+&{
lZ'-?xo
public String getSFilePath() +eg$Z]Lht
{ 8lh{ R
return sFilePath; -=I*{dzly
} B>Mr/'
x!"S`AM
qQv?J]l
public void setSFilePath(String value) :D`ghXj
{ 1$]4g/":o
sFilePath = value; Ol"*(ea-TX
} 615, P/
bzz=8n
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public String getSFileName() -y;SR+
{ -L}crQl.'c
return sFileName; 89?$xm_m
} *+{umfZy
aOFF"(]Cl
|t5K!?{i
public void setSFileName(String value) Y<0 [_+(
{ #XE`8$
sFileName = value; E=+v1\t)]
} a=>PGriL
Ew~piuj
,Y6Me+5B
public int getNSplitter() v,#*%Gn`%
{ =yJJq=!
return nSplitter; >vF=}1_L
} A M8bem~
o|FRG{TJ
J39,x=8LL
public void setNSplitter(int nCount) GSj04-T"
{ sN.h>bd
nSplitter = nCount; 4IuQQ
} C(qqGK{
} j?K]0j;
a*@ 6G
rf?Q# KM\W
/* n@r'b{2;l
**Utility.java Q[O[,Rk
*/ </(bwc~2
package NetFox; $$_aHkI j
K6d9[;F
(P&~PJH
public class Utility { -*t4(wT|j
Uax[Zh[Cg
~vgm;O
public Utility() `],'fT|,S
{ &>y[5#qOl
r*'a-2Au
hY XH9:
} k\rzvo=U
Rl@k~;VV
//线程睡眠 xrd@GTaI
public static void sleep(int nSecond) {W*_^>;K
{ H.cN(7LXm
try{ xO"fg9a
Thread.sleep(nSecond); gIa/sD2m>
} ?$T!=e"
catch(Exception e) s=9gp$9m
{ tp"dho
e.printStackTrace (); %QH "x`;
} bAS('R;4
} oVk*G
'_!j9A]g
//日志 7.@$D;L9
public static void log(String sMsg) tCH4-~,#
{ OW!cydA-
System.err.println(sMsg); SUwSZ@l^|
} (:v|(Gn/
Qvo(2(
BBnW0vAZ*
public static void log(int sMsg) =g|e-XC
{ t-7^deG'/n
System.err.println(sMsg); +s?0yH-%p
} |eH>55 b
} e%.Xya#\
Hg$t,\j
~u|k1
/* R+,eXjz"
**TestMethod.java m:U.ao6
*/ :KY920/,
package NetFox; lYEMrr!KQw
M| r6"~i
evOyTvc
public class TestMethod { qOOF]L9r%u
{hYH4a&Hb
4pNIsjl}
public TestMethod() G=?2{c}U
{ ///xx/weblogic60b2_win.exe (3PkTQlE
try{ -XNjyXm2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {KkP"j'7h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V}<Hx3!
SiteFileFetch fileFetch = new SiteFileFetch(bean); P>q"P1&{
fileFetch.start(); `\!oY;jk
} R&Mv|R
catch(Exception e){e.printStackTrace ();} .<uxZ
Z+%Uwj
\z'A6@
} []B9Me
1HOYp*{#wP
R1$O)A}k
public static void main(String[] args) zzmZ`Ya
{ VK)1/b=yT
new TestMethod(); UykOQ-2-n
} 2ZHeOKJ-
} 3u]#Ra~5
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