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)); ?B ;+,
} G)5w_^&%
for(int i=0;i<nEndPos.length-1;i++) ZN>oz@jY
{ GJz d4kj
nEndPos = nStartPos[i+1]; Z$!>hiz2
} B:S/ ?v
nEndPos[nEndPos.length-1] = nFileLength; BwtjTwd
} ucP}( $
} &LM@_P"T
,l`4)@{G
x95[*[
//启动子线程 t mAj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g a|RW0
for(int i=0;i<nStartPos.length;i++) ,!+>/RlJ
{ m<L.H33'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rT$J0"*=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =9$hZ c
nStartPos,nEndPos,i); gi!{y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2mUq$kws
fileSplitterFetch.start(); SKf9 yS#
} ut z.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =" Q5Z6W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lZoy(kdc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \.h!'nfF
nEndPos = " + nFileLength); Xv;} !z
// fileSplitterFetch[nPos.length-1].start(); sYnf #'
XnC`JO+7M
2eErvfC[
//等待子线程结束 YEfa8'7R
//int count = 0; w@&g9e6E
//是否结束while循环 ph\KTLU
boolean breakWhile = false; 0>hV?A
F FHk0!3
P,5gaT)
while(!bStop) J6pQ){;6
{ q]Y [W1
write_nPos(); 4oW6&1
Utility.sleep(500); Y1RiuJtL
breakWhile = true; ?EP>yCR9
BR\3ij
qr>:meJy4
for(int i=0;i<nStartPos.length;i++) R'RLF =
{ Hq9yu*!u
if(!fileSplitterFetch.bDownOver) ;xF5P'T?|
{ ~=HrD?-99p
breakWhile = false; 1.\|,$
break; 3S4'x4*
} 5J!ncLNm{
} H9nVtS{x
if(breakWhile) 9W{`$30
break; LASR*
.)Xyzd
g/H:`J
//count++; <vS J<WY
//if(count>4) S[p.`<{J
// siteStop(); 7_t\wmvYp
} +$Q.N{LV
,<iJ#$: Sx
!YD~o/t@|
System.err.println("文件下载结束！"); EHpIbj;n
} Y r3h=XY
catch(Exception e){e.printStackTrace ();} CZ&VP%
} PDN3=PAR/A
.48Csc-
5 :O7cBr
//获得文件长度 m$nT#@l5bH
public long getFileSize() C1=7.dPr
{ s;oDwT1
int nFileLength = -1; i=b<Mz7|
try{ s9t`!
URL url = new URL(siteInfoBean.getSSiteURL()); T)%34gN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [I/f(GK
httpConnection.setRequestProperty("User-Agent","NetFox"); 4`Com~`6"
Y1e>P
r!Ujy .R
int responseCode=httpConnection.getResponseCode(); {2u#Q7]|
if(responseCode>=400) aLr\Uq,83
{ m1,?rqeb
processErrorCode(responseCode); 9qyA{ |3
return -2; //-2 represent access is error yEYlQ=[#
} OVr, {[r
TR2X' `:O
CX](^yU_
String sHeader; CKJ9YKu{W
/8V#6d_
Jpi\n- d!
for(int i=1;;i++) "[f"h
{ 32DT]{-N!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3;fuz Kk@b
//Utility.log(in.readLine()); osKM3}Sb
sHeader=httpConnection.getHeaderFieldKey(i); z[xi
if(sHeader!=null) vZEeb j
{ "Mt4~vy
if(sHeader.equals("Content-Length")) Wi a%rm
{ `-)!4oJ]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _Wcr'*7
break; }e}J6[wP
} H(qDQqJHYy
} W<Ms0
else 7:fC,2+
break; 0bY}<x(;
} 4;G:.k!K
} :?1r.n
catch(IOException e){e.printStackTrace ();} J*)Vpk
catch(Exception e){e.printStackTrace ();} CiE
h-0sDt pR
'FB?#C%U
Utility.log(nFileLength); 6=V&3|"
T /iKz
Yh`P+L
return nFileLength; p-]vf$u
} &\(p<TF
W/*2I3a
,TrrqCw>
//保存下载信息（文件指针位置） dP8b\H
private void write_nPos() $umh&z/
{ WfbG }%&J
try{ Y02 cX@K6
output = new DataOutputStream(new FileOutputStream(tmpFile)); SKTf=rY
output.writeInt(nStartPos.length); 5<o8prtB
for(int i=0;i<nStartPos.length;i++) >T*/[{L8;
{ U68o"iE
// output.writeLong(nPos); lR5< G
output.writeLong(fileSplitterFetch.nStartPos); Wn*>h'R
output.writeLong(fileSplitterFetch.nEndPos); +5n,/YjS`
} xO8-vmf2
output.close(); :1Jg;G
} #{973~uj
catch(IOException e){e.printStackTrace ();} Xg>nb1e
catch(Exception e){e.printStackTrace ();} R"Q=U}?$
} \x JGR!
.h)o\6Wq
uyr56
//读取保存的下载信息（文件指针位置） 9 yH/5'
private void read_nPos() <gU^#gsGra
{ X"V,3gDG
try{ ImJ2tz6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P,xI3U< q
int nCount = input.readInt(); T7f>u}T
nStartPos = new long[nCount]; IipG?v0z~
nEndPos = new long[nCount]; #]nH$Kq
for(int i=0;i<nStartPos.length;i++) sFNBrL
{ }Dk*Hs^E
nStartPos = input.readLong(); H8[L:VeNT
nEndPos = input.readLong(); Fb#_(I[aj
} wLeP;u1
input.close(); 8l(_{Y5(-
} fVCpG~&t
catch(IOException e){e.printStackTrace ();} w_-v!s2
catch(Exception e){e.printStackTrace ();} }S{#DgZ@X
} RhVQVjc
8BUPvaP<[
m9My
private void processErrorCode(int nErrorCode) '~?\NeO=
{ h-B&m:gD_U
System.err.println("Error Code : " + nErrorCode); zZ3Ko3L%g_
} ,DrE4")4
GC(:}e|
96fzSZS,
//停止文件下载 CB(Qy9C%h[
public void siteStop() 02Z>#AE
{ 2/.Euf
bStop = true; n6T@A;_g
for(int i=0;i<nStartPos.length;i++) qsnZ?hXPp
fileSplitterFetch.splitterStop(); -h&AO\*^W
>;Er[Rywr
mSSDV0Pfn
} `9;:mR $
} ^6=y4t=%F
//负责部分文件的抓取 Y*-#yG9
**FileSplitterFetch.java H.sHXuu
*/ JTuU}nm+
package NetFox; {"<D$*K~
$bQ[H[4l
@dimZsi1
import java.io.*; . IBy'
import java.net.*; ;0lHi4 c0
+an.z3?w
BM+v,hGY
public class FileSplitterFetch extends Thread { Q[t|+RNKv2
Bny3j~*U
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String sURL; //File URL ,k}-I65M*t
long nStartPos; //File Snippet Start Position @ToY,@]e
long nEndPos; //File Snippet End Position a6AD`| U8
int nThreadID; //Thread's ID rt+%&%wt
boolean bDownOver = false; //Downing is over 9&R. <I
boolean bStop = false; //Stop identical m,i@
FileAccessI fileAccessI = null; //File Access interface >sW9n[
3ifQKKcR{
#'}?.m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Zo}O,;(F5
{ .W_'6Q+
this.sURL = sURL; P@Oq'y[
this.nStartPos = nStart; i v7^!
this.nEndPos = nEnd; I5[HD_g:
nThreadID = id; >BU"C+a8g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,DUD4 [3
} 906b=
wO6 D\#
@BbqYX
public void run() Wr.G9zq.+
{ tz#Fy?pe
while(nStartPos < nEndPos && !bStop) 6?an._ C
{ %3B0s?,I
!9yOFd_
dQSX&.<c,
try{ 5>{S^i~!
URL url = new URL(sURL); 4-RzWSFbo`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @J"Gn-f~
httpConnection.setRequestProperty("User-Agent","NetFox"); L4bx [
String sProperty = "bytes="+nStartPos+"-"; "<f"r#
httpConnection.setRequestProperty("RANGE",sProperty); '1|FqQ\.
Utility.log(sProperty); +AGI)uQQ
iTf]Pd'
Ae,P&(
InputStream input = httpConnection.getInputStream(); |KF_h^
//logResponseHead(httpConnection); =+{SZh@
X6lkz*M.
(* WO<V
byte[] b = new byte[1024]; [ +w=
int nRead; u>R2:i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I_|@Fn[>
{ C"`,?K(U
nStartPos += fileAccessI.write(b,0,nRead); 9?8Yf(MC%u
//if(nThreadID == 1) no6q3<re
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *&7F(
} H_H3Gp
O}Y& @V%4k
~4e4Gyx c
Utility.log("Thread " + nThreadID + " is over!"); mQ# 0c_
bDownOver = true; p:kHb@
//nPos = fileAccessI.write (b,0,nRead); -:mT8'.F-
} 'Em5AA`>
catch(Exception e){e.printStackTrace ();} WCf?_\cG
} (^x ,
} /l o;:)AiP
?)x"+[2
hzG+s#
//打印回应的头信息 >NL4&MV:
public void logResponseHead(HttpURLConnection con) $9LI v
{ 7OF6;@<
for(int i=1;;i++) zQpF,N<b
{ 5,H,OZ}
String header=con.getHeaderFieldKey(i); 6|h~pH
if(header!=null) 46p%y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &-l(nr]h]
Utility.log(header+" : "+con.getHeaderField(header)); A.`) 0dV
else -u!{8S~wA
break; ZdcG6IG+
} "n,?)
} y2nwDw(xF
Pe-1o#7~W
ElBpF8xJ|o
public void splitterStop() QQ1|]/)
{ CF|4, K)
bStop = true; &x= PAu
} t|/{oAj
d~ m,hCTe
?4G/f<ou
} HN7C+e4U~
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-SF*DZ
/* ~57.0?IK
**FileAccess.java l)1FCDV
*//文件访问(定位，写) x^0MEsR
package NetFox; rV *`0hA1
import java.io.*; 'WF Ey>1#
_VvXE572
B)^uGSW
public class FileAccessI implements Serializable{ -pb>=@Yq
)I/K-zj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \%=GM J^[p
RandomAccessFile oSavedFile; y5oC|v7
long nPos; B<et&r;
$7\!
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public FileAccessI() throws IOException .=I:cniw\r
{ }{3XbvC
this("",0); BRSOE U\=
} oQsls9t
'h]sq{
!:zWhu,
public FileAccessI(String sName,long nPos) throws IOException Imv]V6"D=
{ zG"*B_l}+
oSavedFile = new RandomAccessFile(sName,"rw"); Qj:`[#3?2
this.nPos = nPos; reO^_q'
oSavedFile.seek(nPos); J~"h&>T
} CVk.Ez6
q!r4"#Y"@Z
L("zS%qr
public synchronized int write(byte[] b,int nStart,int nLen) 8Qwn
{ #YEOY#
int n = -1; uaiCyh1:
try{ x JXPtm
oSavedFile.write(b,nStart,nLen); .66_g@1
n = nLen; dc]D 8KX
} ,p3moD 3
catch(IOException e) cz{5-;$9Z
{ TmH'_t.*T~
e.printStackTrace (); y,YK Mc
} S(&]?!
J/-&Fa\(
IN{ 1itE
return n; -JMlk:~
} j$%uip{
#z.QBG@
krt8yAkG
} y?r:`n
vc r5
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/* I7[F,xci
**SiteInfoBean.java JsDugn ,B
*/ e [}m@a
package NetFox; BZdryk:S
Pl9Ky(Q`V
Ho_ 2zx:8b
public class SiteInfoBean { mh5ozv$
ytsPk2@WR
SniKCqmC]
private String sSiteURL; //Site's URL 0QakFt
private String sFilePath; //Saved File's Path =xf7lN'
private String sFileName; //Saved File's Name C{5^UCJkg
private int nSplitter; //Count of Splited Downloading File |1rKGDc
q%rfKHMA50
XH"-sZt
public SiteInfoBean() M8,_E\*
{//nSplitter的缺省值为5 (*XSrQ
//default value of nSplitter is 5 2)W~7GED
this("","","",5); <*4'H
} XZ3)gYQi
E\GD hfTQ
9^AfT>b~f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eHt |O~
{ --t5jSS44
sSiteURL= sURL; .3Ag6YI0N
sFilePath = sPath; Z:e|~#
sFileName = sName; @C=Dk
this.nSplitter = nSpiltter; `g~T #U\>d
S,'y L7s
~"t33U6
} s/"l ?d
;OTd<
?)2&LVrf
public String getSSiteURL() D{Rk9MKkE
{ >&`S$1 o
return sSiteURL; m:sT)
} p2\mPFxEP
FK:Tni
\{Yi7V Xv
public void setSSiteURL(String value) .dr-I7&!
{ tt%lDr1A)
sSiteURL = value; U>@st="
} hM/:zC:
%^){)#6w
>bo_
public String getSFilePath() 55<f
{ eX1<zzd
return sFilePath; Px$4.b[{_Y
} fzhCV
<,Z6=M`
"F.0(<4)
public void setSFilePath(String value) TSPFi0PP
{ lZI?k=rWv
sFilePath = value; m%[Ul@!V
} MD62ObK!
=;!$Qw4
jJB+UF=
public String getSFileName() =MP?aH [
{ ;%/Kh :Vg
return sFileName; b;AGw3SF
} e2@{Ab
i!U,qV1
W-ctx"9DS
public void setSFileName(String value) k>ERU]7[
{ GCEcg&s=\S
sFileName = value; T`?{Is['(
} V7pe|]%r
{~lVe GBp
RdtF5#\z
public int getNSplitter() ;rK= jz^Q
{ %xH2jf
return nSplitter; =HGC<#
} js~?y|e8k
7H~J?_
ap7ZT7KW
public void setNSplitter(int nCount) a'U}.w}
{ /%P|<[< [
nSplitter = nCount; x_yQoae
} $^ wqoW%t
} #"6O3.P
c[h{C!d1
DviRD[+q"
/* Ns*&;x9
**Utility.java aJmSagr69C
*/ rda/
package NetFox; R[l9f8
.>.B
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public class Utility { .0[ zZ
x bsk
8^8fUN4<=
public Utility() RF,[1O-\O
{ Vh1R!>XY
Qel2OI`b
+5>*$L%8T`
} cKbjW
X/8CvY#n
//线程睡眠 Bj-80d,
public static void sleep(int nSecond) Wvg+5Q
{ &:3uK`
try{ t04_~e
Thread.sleep(nSecond); bu j}pEI
} W'B=H1
catch(Exception e) ?c$z?QTMJ
{ k/hD2tBLu
e.printStackTrace (); de&*#O5
} zOEdFU{x
} R;6$lO8C&
\m\E*c ):
//日志 PqhR^re0.
public static void log(String sMsg) %O=U|tuc$
{ !(-lY(x
System.err.println(sMsg); gYtv`O
} *j9hjq0j
Hw(_l,Xf
Ui^~A
public static void log(int sMsg) zn=Ifz)#|
{ YEg(QOn3Q
System.err.println(sMsg); =.sg$VX
} 2%|0c\y|z=
} mHiV};$
S1!X;PP/
z;#DX15Rj
/* ^~iFG+g5
**TestMethod.java tz).]E D
*/ 8c6dTT4
package NetFox; qir/Sa'[
4IT`8n~
(iT?uMRz
public class TestMethod { 5f` a7R
GmONhh(k
lVw77bZ
public TestMethod() >Z\{P8@k0
{ ///xx/weblogic60b2_win.exe YM:;mX5B
try{ '1jG?D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3>+9Rru
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r&MHww1i
SiteFileFetch fileFetch = new SiteFileFetch(bean); 24}?GO
fileFetch.start(); S~ff<A>f
} b,k%n_&n
catch(Exception e){e.printStackTrace ();} rmzM}T\20
Ub(8ko:8$
nQ$4W
} {#Lj,o
LhfI"fc
na5:)j4<
public static void main(String[] args) j.b7<Vr4;
{ h0=Q.Yz6
new TestMethod(); (F<VcB
} 0Bo7EV
} ?tf/#5t}
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