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)); g!`BXmW
} ,$i<@2/=m
for(int i=0;i<nEndPos.length-1;i++) 0(vdkC4\A
{ X0x_+b? _
nEndPos = nStartPos[i+1]; I:/4t^%
} -CElk[u
nEndPos[nEndPos.length-1] = nFileLength; ZW2s[p r
} [5LMt*Y
} aZ/yCS7
Rc%PZ}es
fSC.+,qk
//启动子线程 `g8tq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3It8&x:
for(int i=0;i<nStartPos.length;i++) %f#\i#G<k
{ Jh(mbD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mE_iS?1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DD6'M U4
nStartPos,nEndPos,i); A xR\ned
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &u4Ve8#
fileSplitterFetch.start(); z{V8@q/
} PE7t_iSV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >!G5]?taa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E$&;]a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .)nCOwR6p
nEndPos = " + nFileLength); ;l#?SYY
// fileSplitterFetch[nPos.length-1].start(); U*xxrt/On/
,"C&v~
:9O|l)N)W=
//等待子线程结束 `0[fLEm
//int count = 0; SJF2k[da
//是否结束while循环 ~:s!].H
boolean breakWhile = false; ~s0P FS7
L]a|vp
%SFw~%@3&~
while(!bStop) y(ldO;.
{ j~Ff/O
write_nPos(); tpd|y|
Utility.sleep(500); '&{(:,!B
breakWhile = true; z8tt+AU
!?Tzk&'
aEZJNWv
for(int i=0;i<nStartPos.length;i++) p?KCVvx$
{ @+Pf[J41
if(!fileSplitterFetch.bDownOver) t>-XT|lV
{ 5\5~L
breakWhile = false; o+R. u}|
break; 1dXh\r_n
} {vCU^BN,k
} V?o&])?[
if(breakWhile) `oan,wq+
break; f3\w99\o
7~ILRj5Nq
\J\vp0[nO}
//count++; g<;Nio
//if(count>4) _4g}kL02.
// siteStop(); hkLw&;WJr
} 6l=M;B7:i
1gL8$.B?
Z*;*I<-
System.err.println("文件下载结束！"); )/i4YLO
} X^9t
catch(Exception e){e.printStackTrace ();} 8F.(]@NY
} H?ieNXP7{
^S3A10f,
X{4xm,B/
//获得文件长度 ta2z
public long getFileSize() Iy-u`S
{ :r[W'h_%
int nFileLength = -1; KF*B
try{ ]IL3$eR
URL url = new URL(siteInfoBean.getSSiteURL()); "P9wT)J_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xU:PhhS
httpConnection.setRequestProperty("User-Agent","NetFox"); :s? y,
((n5';|N
; \Y-
int responseCode=httpConnection.getResponseCode(); o(vZ*^\
if(responseCode>=400) X/K| WOO6
{ eDvXU_yA
processErrorCode(responseCode); {_+>"esc
return -2; //-2 represent access is error cM|af#o
} 06Sqn3MB
NN?Bi=&9
E]D4']
String sHeader; #{.pQi})
=#J9
Q2??Kp]1
for(int i=1;;i++) <$Xn:B<H
{ i,\t]EJAU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,|=iv
//Utility.log(in.readLine()); )yfOrsM
sHeader=httpConnection.getHeaderFieldKey(i); >0[qi1
if(sHeader!=null) &L2`L)
{ +G>aj'\M|
if(sHeader.equals("Content-Length")) v#zfs'
{ p=je"{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?d,acm
break; w4>:uyE
} uBV^nUjS"m
} KX&Od@cQ$
else )i?{;%^
break; e{d_p%(
} 'bd=,QW
} 7~QwlU3n<F
catch(IOException e){e.printStackTrace ();} zcbA)
catch(Exception e){e.printStackTrace ();} 9;'>\ImI
V~tu<"%
E9 :|8#b
Utility.log(nFileLength); Xb8:*Y1'
Q|zE@nLS
}6b7a1p
return nFileLength; 5[0l08'D
} `3H?*\<(
*&~sr
gb^UFD L
//保存下载信息（文件指针位置） 70I4-[/z[d
private void write_nPos() A_8`YN"Xk
{ `RL(N4H
try{ $/-wgyP3m+
output = new DataOutputStream(new FileOutputStream(tmpFile)); gDjd{+LUo
output.writeInt(nStartPos.length); @vDgpb@TM
for(int i=0;i<nStartPos.length;i++) 1-ndJ@Wlz
{ c9/ 'i
// output.writeLong(nPos); =[O<.'aG-
output.writeLong(fileSplitterFetch.nStartPos); FeincZ!M
output.writeLong(fileSplitterFetch.nEndPos); >(YPkmH
} g@N=N
output.close(); <'+R%6
} fM zAf3
catch(IOException e){e.printStackTrace ();} P,LXZ
catch(Exception e){e.printStackTrace ();} I NFzX
} V9);kD
"J0Oa?
B_6v'=7]
//读取保存的下载信息（文件指针位置） vf/$`IJ
private void read_nPos() s}pGJ&C
{ (h8hg+l o
try{ x Jj8njuq4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Vf\?^h(tP
int nCount = input.readInt(); 6H. L!tUI
nStartPos = new long[nCount]; E2ayK> ,
nEndPos = new long[nCount]; KX=:)%+
for(int i=0;i<nStartPos.length;i++) 4jue_jsle
{ e`gGzyM
nStartPos = input.readLong(); /ltP@*bo
nEndPos = input.readLong(); }rb ]d'|
} 8Y;zs7Y
input.close(); :9O0?6:B|
} Cq~ah
catch(IOException e){e.printStackTrace ();} d5Eee^Qu/
catch(Exception e){e.printStackTrace ();} `)xU;-
} fQ?n(
8u~\]1(
IU;pkgBj0Y
private void processErrorCode(int nErrorCode) vYTPZ@RL
{ PK|`}z9
System.err.println("Error Code : " + nErrorCode); Z-;uzx
} n?ZH2dI\0
:[ZC-hc\
h-)A?%Xt
//停止文件下载 J 6d n~nPK
public void siteStop() _<' kzOj
{ Vzv.e6_
bStop = true; QYCNO#*
for(int i=0;i<nStartPos.length;i++) P*qNRP%
fileSplitterFetch.splitterStop(); BIB>U W
[laL6
WRU@i;l
} ,BN}H-W\2
} 9"u@<]
//负责部分文件的抓取 C`K9WJOD
**FileSplitterFetch.java qjRiTIp9q
*/ I! eSJTN
package NetFox; H:nu>pzt
y^+[eT&
9W,}AWf:Y
import java.io.*; 9@&Z`b_
import java.net.*; 1Qc(<gM
yP=isi#dDY
qytGs@p_
public class FileSplitterFetch extends Thread { qh'f,#dI}
H ]N/Y{
rF j)5~
String sURL; //File URL '<E8<bi
long nStartPos; //File Snippet Start Position Xrzh*sp
long nEndPos; //File Snippet End Position Wx\"wlJ7.3
int nThreadID; //Thread's ID x /Ky: Ky
boolean bDownOver = false; //Downing is over k:uuJ|
boolean bStop = false; //Stop identical TB3T:A>2
FileAccessI fileAccessI = null; //File Access interface t>=y7n&q
1V9X(uP
DEeL48{R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xo"4mbTV
{ 0bQiUcg/
this.sURL = sURL; QCY{D@7T
this.nStartPos = nStart; So]FDd
this.nEndPos = nEnd; NS/L! "g
nThreadID = id; nO7o7bc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D+U/]sW
} y&I|m
X52jqXjg
4lKbw4[a
public void run() .j4ziRa-
{ ~v,KI["o
while(nStartPos < nEndPos && !bStop) Z 5YW L4s
{ :phD?\!w8t
%a6]gsiv2<
JFk|Uqs(
try{ _q 9lr8hx
URL url = new URL(sURL); q,>F#A'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WD do{
httpConnection.setRequestProperty("User-Agent","NetFox"); X}QmeY[0I
String sProperty = "bytes="+nStartPos+"-"; (7#lN
httpConnection.setRequestProperty("RANGE",sProperty); %T*+t"\)
Utility.log(sProperty); pvdZ>D-IU
8gKR<X.G
PY:#F|uHS`
InputStream input = httpConnection.getInputStream(); =y(YMWGS
//logResponseHead(httpConnection); !'t2
3g "xm
- 5Wt9
byte[] b = new byte[1024]; }8]uZ)[p=
int nRead; .A[.?7g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JfINAaboi
{ ,* vnt6C*
nStartPos += fileAccessI.write(b,0,nRead); (cew:z H
//if(nThreadID == 1) '\mZ7.Jj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $YQ&\[pDA
} O]LuL&=s y
ZV^J5wYE
Fmle|
Utility.log("Thread " + nThreadID + " is over!"); MifgRUe
bDownOver = true; HNyDWD)_
//nPos = fileAccessI.write (b,0,nRead); c]0
} +rw3.d
catch(Exception e){e.printStackTrace ();} fJlN'F7
} MAo,PiYb
} 5GxM?%\
`.-k%2?/
[hj'Yg8{
//打印回应的头信息 Bw7:ry
public void logResponseHead(HttpURLConnection con) @"7dk.|
{ Br^b%12ZRS
for(int i=1;;i++) Llc|j&yHQ
{ >f05+%^[
String header=con.getHeaderFieldKey(i); pXlBKJmW
if(header!=null) `i^1U O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _~q^YZ
Utility.log(header+" : "+con.getHeaderField(header)); _qo1 GM&
else utS Mx(
break; KgAX0dM
} ~{!!=@6
} M#2U'jy
@Iatlz*W
0x/V1?gm
public void splitterStop() &WU*cfJn)A
{ gUtbCqDS
bStop = true; &t:MWb;
} Ym2m1
A2bV[+Q
g%P4$|C9i
} Vta;ibdeqW
5DUPsV
df rr.i
/* 3AL=*qq
**FileAccess.java Q>*K/%KD
*//文件访问(定位，写) gb#wrI
package NetFox; :6iq{XV^
import java.io.*; &4iIzw`
/VZU3p<~
6)j4 TH
public class FileAccessI implements Serializable{ raZRa*C;
yiA\$mtO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 En_8H[<%
RandomAccessFile oSavedFile; Kg67cmj)f
long nPos; dju{&wo~4
FKm2slzb
"t`e68{Ls
public FileAccessI() throws IOException u)MA#p {
{ .lS6KBf@
this("",0); 0zNS;wvv&
} 4Lb<#e13R?
>R-$JrU.=
Bv*h?`Q
public FileAccessI(String sName,long nPos) throws IOException \hc9Rk
{ Wm_-T]#_
oSavedFile = new RandomAccessFile(sName,"rw"); ^O"`.2O1
this.nPos = nPos; 2yc\A3ft#
oSavedFile.seek(nPos); '|r!yAO6
} Q+N @j]'
<(%uOo$
:9qB{rLi}
public synchronized int write(byte[] b,int nStart,int nLen) v1rGq
{ k/Q]Ke
int n = -1; >s~`K^zS
try{ h {btT
oSavedFile.write(b,nStart,nLen); 5%/%i}e~(
n = nLen; $OuA<-
} $a1.c;NE'
catch(IOException e) oLRio.u*
{ H#akE\,
e.printStackTrace (); uBJF}"4ej
} M-t9zT
|Dli6KN
LYv2ll`XP
return n; kXRD_B5&
} *i90[3l
JH9CN
#2iA-5
} dksnW!
sS|5x
$^F2
/* y.OUn'^d4
**SiteInfoBean.java S8t9Ms: k
*/ KDk^)zv%!
package NetFox; 9m>_qWaA
C^'}{K
3]A'C&
public class SiteInfoBean { KxI(#}5o&
>ZWm0nTr
='azVw%_
private String sSiteURL; //Site's URL )JON&~C
private String sFilePath; //Saved File's Path XZJx3!~fm
private String sFileName; //Saved File's Name 5@\<:Zmi
private int nSplitter; //Count of Splited Downloading File dfce/QOV
EY(4<;)
NKN!X/P
public SiteInfoBean() Ft7l/
{//nSplitter的缺省值为5 DoA f,9|_
//default value of nSplitter is 5 aQuENsB
this("","","",5); gUlZcb
} E.brQx#}
0jq#,p=l;
Hr'#0fW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IAQ=d4V&
{ EhoR.
sSiteURL= sURL; -i4gzak
sFilePath = sPath; ! >V1zk
sFileName = sName; LE"xZxe
this.nSplitter = nSpiltter; -lHJ\=
/V~(!S>
Fej$`2mRH
} ?Eed#pb_
?IWS
H.e@w3+h
public String getSSiteURL() =W?c1EPLCx
{ ;#*mB`
return sSiteURL; -\vq-n
} <@P0sd
@g{ " E6
uM$=v]e^4
public void setSSiteURL(String value) W\/0&H\i
{ AkF3F^
sSiteURL = value; X9>ujgK
} Fc Cxr@
`*B8IT)
BehV :M
public String getSFilePath() ! JN@4
{ XT\;2etVL
return sFilePath; |?8wyP
} Oc1ZIIkh\
WO^h\#^n
xxYFWvi
public void setSFilePath(String value) vv3?ewr y
{ G.;<?W
sFilePath = value; FM5$83Q
} - >2ej4C
[(1O_X(M
=0A{z#6
public String getSFileName() s<{c?4T
{ "D+QT+sD
return sFileName; +KZc"0?
} X~0P+E#
yTk9+>
-kkXyO8js
public void setSFileName(String value) |( KM 8
{ B}p/ ,4x6
sFileName = value; Gl+}]Vn[n
} Eyuc~[
^^Y0 \3.
H74hv`G9
public int getNSplitter() 0x84 Ah)
{ ({)_[dJ'
return nSplitter; q /#O :Q
} $O[ut.
M30_b8[Y_
w ^A0l.{
public void setNSplitter(int nCount) M9MEQK
{ e.Ii@<
nSplitter = nCount; ZyTah\yPM
} ?r/7:
} lD(d9GVm{z
X6PfOep
SngV<J>zR
/* 0\/7[nwS
**Utility.java /H)l\m +
*/ )K}b,X`($
package NetFox; cWm.']
]uP{Sj
R1U\/
public class Utility { f,$FrI,
H_x35|"
bF3j*bpO"
public Utility() uzsR*x%s-
{ 79&Mc,69
KxvT}"k
+_+_`q>]
} ym:JtI69
Cnc77EUD
//线程睡眠 zX3O_
public static void sleep(int nSecond) 8ciLzyrY*
{ UZV)A}
try{ "?]5"lNC|
Thread.sleep(nSecond); 8s|r'
} ~_K
catch(Exception e) Dq\#:NnKvx
{ :D(:(`A=
e.printStackTrace (); P0W%30Dh
} X(bb1
} %o~zsIl
0DN:{dJz
//日志 3o/f#y
public static void log(String sMsg) uH`ds+Hp
{ 0<e7!M=U1
System.err.println(sMsg); <>-UPRwqI
} "<=^Sm
A:N!H_x
fY>\VY$>
public static void log(int sMsg) !\p-|51
{ Um%E/0j
System.err.println(sMsg); |%$d/<<PZ
} l*h6JgU
} A+?n=IHh
]t<%v_K
/+'@}u |
/* -5.>9+W8I
**TestMethod.java _,vJ0{*
*/ 5"{wnnY%K}
package NetFox; 9)wjVk
kQ|}"Tw7
|s|RJA1
public class TestMethod { X~lOFH;}q
guBOR0x`
MTr _8tI
public TestMethod() vG<Mz?wr
{ ///xx/weblogic60b2_win.exe 1V)0+_Yv
try{ Y8Mo.v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <&:3|2p
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \@5W&Be^
SiteFileFetch fileFetch = new SiteFileFetch(bean); | YvO$4=s
fileFetch.start(); Yh"R#
} S7-?&[oeJ
catch(Exception e){e.printStackTrace ();} Dz.U&+*
Rb#?c+&#
5FzG_ w
} V$@@!q
w W-GBY3
6Bs_" P[
public static void main(String[] args) GMksr%0Pj
{ S# SA:>8s
new TestMethod(); N+h|Ffnp
} WC}mt%H*O
} n_iq85
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