http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); \Kl+ 5%L
} i 7_ _
for(int i=0;i<nEndPos.length-1;i++) /e7O$L)
{ ^.#jF#u~
nEndPos = nStartPos[i+1]; J/\V%~ 1F
} fIj|4a+
nEndPos[nEndPos.length-1] = nFileLength; nN*w~f"
} QrfG^GID
} 'qjeXqGH$
JQV%fTHS
LA@w:Fg
//启动子线程 yHs-h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dQ_!)f&w1
for(int i=0;i<nStartPos.length;i++) O$IEn/%+
{ F{EnOr`,m=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \]=7!RQ\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kB/D!1 "
nStartPos,nEndPos,i); ,=tD8@a<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |p><'Q%*
fileSplitterFetch.start(); KHgBo}6
} @n(Z$)8tR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l7W 6qNB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pdt6nzfr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZkAU17f
nEndPos = " + nFileLength); D[^m{ 9_
// fileSplitterFetch[nPos.length-1].start(); 5!l0zLQPo
wS4.8iJ
RT)d]u
//等待子线程结束 Fe]B&n
//int count = 0; Rn{iaM2Y<
//是否结束while循环 T'4z=Z]w
boolean breakWhile = false; +w.JpbQ&
I 4,K43|
FP;Ccl"s
while(!bStop) AI,(z;{P
{ U7oo$gW%|T
write_nPos(); Hz.(qW">5*
Utility.sleep(500); QS{1CC9$
breakWhile = true; u[L`-zI
3 |hHR
7qj9&bEy
for(int i=0;i<nStartPos.length;i++) oXxCXO,q
{ J]&y$?C
if(!fileSplitterFetch.bDownOver) 'h^0HE\~p
{ ^1Zeb$Nw'
breakWhile = false; #$c Rkw
break; |g #K]v
} bzX\IrJpOZ
} 6ek;8dL
if(breakWhile) JMH8MH*
break; 5dB'&8DX
D9FJ 1~
c0hwc1kv-
//count++; @6mBqcE'?
//if(count>4) d/bEt&
// siteStop(); yqi^>Ce0
} WDg+J
hir4ZO%Zt
pek%08VSEU
System.err.println("文件下载结束！"); #B:hPZM1
} #|*F1K
catch(Exception e){e.printStackTrace ();} %,Ap7X3:QT
} :{oZ~<
~-PjW#J%
JaK}|
//获得文件长度 ,t`Kv1
public long getFileSize() TZ2=O<Kj
{ :'*DPB-
int nFileLength = -1; 7vABq(
try{ `67[O4$<
URL url = new URL(siteInfoBean.getSSiteURL()); 6IWxPt~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {%IExPJ
httpConnection.setRequestProperty("User-Agent","NetFox"); r=6v`)Qr
/)dFK~
|\U5),m
int responseCode=httpConnection.getResponseCode(); )l!3(
if(responseCode>=400) DqX{'jj
{ u$-U*r
processErrorCode(responseCode); zOGU8Wg
return -2; //-2 represent access is error (iRide
} I =1+h
Clh!gpB c
<<i3r|}
String sHeader; (y M^
BM(]QUxRd
'3<fsK=
for(int i=1;;i++) w^LuIbA
{ 7DIIx}A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jLpc Zb,
//Utility.log(in.readLine()); cCa|YW^j
sHeader=httpConnection.getHeaderFieldKey(i); NcP.;u;`
if(sHeader!=null) gS:A'@&
{ Oi:<~E[kz.
if(sHeader.equals("Content-Length")) ^D<r
{ Ur5FC r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "m^' &L
break; ^`G`phd$
} TEMw8@b
} 1P(|[W1
else TOoQZTI
break; r\blyWi
} i:Zm*+Gi
} $2u 'N:o
catch(IOException e){e.printStackTrace ();} +e-G,%>9
catch(Exception e){e.printStackTrace ();} jiYmb8Q4D
ZKXo-~=>
fgBM_c&9T
Utility.log(nFileLength); c7M%xGrP
!w H'b
C#H:-Q&
return nFileLength; i| ZceX/
} mWyqG*-Hb
%~jkB.\* )
<D::9c j
//保存下载信息（文件指针位置） KX}Rr7a
private void write_nPos() RKPD4e>%
{ h68]=KyK
try{ .58qL-iC
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4WE6fJ2X
output.writeInt(nStartPos.length); gt/zpiKmV
for(int i=0;i<nStartPos.length;i++) ;L,mBQB?0b
{ Y& F=t/U2
// output.writeLong(nPos); &`fhEN
output.writeLong(fileSplitterFetch.nStartPos); 4[BG#
output.writeLong(fileSplitterFetch.nEndPos); QjC22lW-
} gl]E_%tH
output.close(); cetvQAGXY
} {O+Kw<d
catch(IOException e){e.printStackTrace ();} JMVNmq&0
catch(Exception e){e.printStackTrace ();} NHl|x4Zpw
} 8@PX7!9
+n7?S~R$
l27\diKPJ
//读取保存的下载信息（文件指针位置） TuW/N L|
private void read_nPos() .S%0
{ JkGnKm9G
try{ %%Qo2^-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rYp3(k3
int nCount = input.readInt(); Fh*j#*oe
nStartPos = new long[nCount]; wQ%mN[
nEndPos = new long[nCount]; [|lB5gi4t!
for(int i=0;i<nStartPos.length;i++) doB
{ 7^M9qTEHp
nStartPos = input.readLong(); /l{&iLz[
nEndPos = input.readLong(); m~>Y{F2
} 7#~+@'Oe
input.close(); t#S<iBAZ
} ay %KE=*v
catch(IOException e){e.printStackTrace ();} <&!v1yR
catch(Exception e){e.printStackTrace ();} 7Su#Je]
} YhRWz=l
Dk='+\
sO5?aB&
private void processErrorCode(int nErrorCode) o=RM-tR`v
{ zz^F k&
System.err.println("Error Code : " + nErrorCode); 5P .qXA"D
} JMCW}bA
qiZO _=0
gh>>Ibf
//停止文件下载 IQ!\w-
public void siteStop() gaf$uT2
{ /1 RAAa
bStop = true; x)UwV
for(int i=0;i<nStartPos.length;i++) !J=sk4T
fileSplitterFetch.splitterStop(); 4HAp{a1
||zb6|7I4
h!#:$|Q
} Sggq3l$Qc
} 0oh]61gC
//负责部分文件的抓取 E0/mSm"(T
**FileSplitterFetch.java Z--@.IYoJ
*/ 9z I.pv+]
package NetFox; `y+-H|%?
1.D-FPK
CdUAy|!`R
import java.io.*; N-g8}03
import java.net.*; {} Bf
j&UMjI9[
"/]| Hhc{
public class FileSplitterFetch extends Thread { v?c 0[+?
g}f9dB,F
Bk}><H
String sURL; //File URL dtPoo\@
long nStartPos; //File Snippet Start Position IG?'zppjd6
long nEndPos; //File Snippet End Position JxjI]SF02
int nThreadID; //Thread's ID "v}pdUW
boolean bDownOver = false; //Downing is over xvNo(>
boolean bStop = false; //Stop identical f/kI|Z
FileAccessI fileAccessI = null; //File Access interface W- $a Y2
5/QRL\
NWfAxkz{/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XM<KF&pVB
{ x"4} isp<
this.sURL = sURL; \7z^!m
this.nStartPos = nStart; <}jPXEB"
this.nEndPos = nEnd; =H8 xSJLh
nThreadID = id; 4gSH(*}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ICB~_O5
} jEz+1Nl)
@=5qT]%U3J
nJ?^?M'F%
public void run() L&-hXGx=7
{ 0e[d=)XG
while(nStartPos < nEndPos && !bStop) =op%8NJf
{ qi^!GA'5j
^Cv^yTj;&
d/74{.
try{ O8U<{jgAG
URL url = new URL(sURL); ,uz ]V1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B$?qQ|0:=
httpConnection.setRequestProperty("User-Agent","NetFox"); ?4G|+yby
String sProperty = "bytes="+nStartPos+"-"; Zs2-u^3&
httpConnection.setRequestProperty("RANGE",sProperty); I =Wc&1g
Utility.log(sProperty); OOBhbpg!D
Zc"B0_&?:7
Q/I)V2a1i
InputStream input = httpConnection.getInputStream(); >\<*4J$PZ
//logResponseHead(httpConnection); }]UB;id'
: t$l.+B
qP!P +'B
byte[] b = new byte[1024]; S<nq8Ebmw
int nRead; _)$PKOzbb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A\Txb_x
{ @^ ik[9^H
nStartPos += fileAccessI.write(b,0,nRead); 2}vg U$a
//if(nThreadID == 1) #(LfYw.P1V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O;[9_[
} "tS'b+SJ-S
ZiFooA
'j%F]CK
Utility.log("Thread " + nThreadID + " is over!"); #kkY@k$4
bDownOver = true; ExHAY|UA
//nPos = fileAccessI.write (b,0,nRead); XH7xT@
} ?RFg$Z'^
catch(Exception e){e.printStackTrace ();} K:y^OAZfV
} :RxHw;!
} s,*c@1f?
DZ ^1s~
s]27l3)B
//打印回应的头信息 fR-C0"c
public void logResponseHead(HttpURLConnection con) W</n=D<,I
{ }i!pL(8;
for(int i=1;;i++) )<4_:
{ {}>n{_
String header=con.getHeaderFieldKey(i); ^]p
if(header!=null) /DS?}I.*]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Wx)K*9
Utility.log(header+" : "+con.getHeaderField(header)); 4YU/uQm
else sTHq&(hLUG
break; o=fgin/E\
} smAC,-6]~
} ^a9 oKI9n
_'x8M
R@T6U:1
public void splitterStop() +:jT=V"X
{ [IM%b~j(^
bStop = true; O,V9R rG
} #6S75{rnW"
MN= sIP,zk
JbQZ!+
} ^%oUmwP<$
b1^n KB
VFD%h }
/* MN;/*t
**FileAccess.java cJ}QXuuUv
*//文件访问(定位，写) oholt/gb+0
package NetFox; CidM(
import java.io.*; eo#^L}
;@4H5p
GtI6[ :1t
public class FileAccessI implements Serializable{ 6DSH`-;
{6vEEU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |@VF.)_
RandomAccessFile oSavedFile; bNzqls$
long nPos; }3/~x
J>S3sP
%.x@gi q
public FileAccessI() throws IOException h!]"R<QQdu
{ X.|Ygx
this("",0); v1[_}N9f>H
} 0^!Gib
hY\{|
nZvU'k:
public FileAccessI(String sName,long nPos) throws IOException J0<p4%Cf
{ f5dR 5G
oSavedFile = new RandomAccessFile(sName,"rw"); l`n5~Fs
this.nPos = nPos; a,Kky^B
oSavedFile.seek(nPos); j=sBq.S
} )GB`*M[
/-*hjX$n
\MYU<6{u
public synchronized int write(byte[] b,int nStart,int nLen) KHj6Tg;)
{ 6!7Pm>ml
int n = -1; +$beo2x6
try{ I ,FqN}
oSavedFile.write(b,nStart,nLen); M?6;|-HH
n = nLen; x(r+P9f\<
} 99ASIC!
catch(IOException e) KjR4=9MD
{ Uxl(96
e.printStackTrace (); L=1~ f-
} $-pbw@7
b6W#SpCF
4Z%Y"PL(K
return n; X.J
} 2)LX^?7R
/(6zsq'v|
}ymvC
} #Q6w+"
]if;A)'
{/UhUG
/* I"Q<n[g0'
**SiteInfoBean.java ua& @GXvZ
*/ U}P,EP%p
package NetFox; Kmry=`=A
LcUlc)YH5
r\mPIr|
public class SiteInfoBean { j 2}v}
(wL3 +
X5E '*W
private String sSiteURL; //Site's URL i-13~Dk
private String sFilePath; //Saved File's Path !UNNjBBP7
private String sFileName; //Saved File's Name ^8742.
private int nSplitter; //Count of Splited Downloading File ?V+wjw
(Pz8iz
R7aXR\ R
public SiteInfoBean() STT2o=
{//nSplitter的缺省值为5 XJFnih
//default value of nSplitter is 5 1i,4".h?M
this("","","",5); wu^q`!ml
} 6F5,3&
Dc:DY:L^
r@$B'CsLj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,C!n}+27
{ *)%dXVf
sSiteURL= sURL; i_Ar<9a~
sFilePath = sPath; wznn #j
sFileName = sName; t,Q'S`eTU
this.nSplitter = nSpiltter; ,8`O7V{W
Q&wYc{TUbm
+u#Sl)F
} cdp{W
qhxC 5f4Z
$h]NXC6J
public String getSSiteURL() j];G*-iv{
{ Ut;'Gk
return sSiteURL; 0Q3YN(
} Qdm(q:w
T{;=#rG<
u9@b<
public void setSSiteURL(String value) \)GR\~z0h
{ d"l}Ny)C
sSiteURL = value; 9TW8o}k`
} $P_x v
K Dz]wNf
O'Am RJ
public String getSFilePath() M/)B" q
{ .r*#OUC
return sFilePath; .]zw*t*
} 0w+5'lOg
L,%Z9
5])8qb/F
public void setSFilePath(String value) ytob/tc
{ r?]%d!
sFilePath = value; K /8qB~J*
} |87W*
d{l{P]nr
8LeKwb
public String getSFileName() TL]bY'%
{ m/KjJ"s,
return sFileName; ,=x RoXYB}
} ?}v}U^
lnjL7x
`L;OY 4
public void setSFileName(String value) Bjtj{B
{ 0ovZ&l
sFileName = value; 67fIIXk&
} 2$
-2z,cj&E{
Qv\bLR
public int getNSplitter() :`;(p{
{ !2wETs?
return nSplitter; VZIKjrKs
} uGM>C"
?&XzW+(X
E"ZEo9y@^
public void setNSplitter(int nCount) `fLfT'
{ S>(z\`1qm
nSplitter = nCount; -#daBx ?
} m_(E(_
} wJ/~q)
GIK u
QT7_x`#J~o
/* s5nB(L*Pjp
**Utility.java 8KZ$F>T]>
*/ Pb3EnNqYbM
package NetFox; Z%KL[R}^w;
|E? ,xWN
|c=d;+
public class Utility { )4Bwt`VX
S'|lU@PCl
:82?'aR
public Utility() \3L$I-]m
{ N:twq&[Y
oO8]lHS?@
Z0{f
} oy`3r5g
EgFl="0
//线程睡眠 l<s :%%CX
public static void sleep(int nSecond) " S ?Km
{ >J9IRAm}sc
try{ JXlTN[O
Thread.sleep(nSecond); gZ1N&/9;
} %bEGv:88s
catch(Exception e) i_|h{JK)
{ *m iONc
e.printStackTrace (); =z+-l5Gu"
} {`tHJ|8
} vY4WQbz(
0PR4g}"
//日志 |&9tU
public static void log(String sMsg) l.sm~/
{ ]~$c~*0g
System.err.println(sMsg); gv`%Z8u(
} ]aREQ?ma&z
*X%?3"WH8
sV]i/B
public static void log(int sMsg) @wg&6uQ
{ Ml'bZLwq
System.err.println(sMsg); loml.e=87
} rve7YS'
} jM{qRfOrg
"vv$%^
'\Qf,%%.
/* @ysJt
**TestMethod.java ;|Y2r^c
*/ D WsCYo
package NetFox; GH[ U!J
U&w*Sb"
6wa<'!
public class TestMethod { 8''9@xz
<{3q{VW*
7Ntjx(b$"h
public TestMethod() s$K@X `
{ ///xx/weblogic60b2_win.exe FEge+`{,
try{ 'SsPx&)l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P9 W<gIO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Dh*~U:6$g
SiteFileFetch fileFetch = new SiteFileFetch(bean); n P0Ziu'{
fileFetch.start(); C~3@M<X
} a.5zdoH_
catch(Exception e){e.printStackTrace ();} b>GqNf!
>^M!@=/?J
I|Vk.,
} N )b|
at_dmU2[7
5JJg"yuY"
public static void main(String[] args) J R8 Z6
{ s@*,r@<
new TestMethod(); X; e`y:9
} -`<6=[QUO
} 8Cf^$
点击下载更多相关资料