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)); j_?cpm{~ml
} FgA//)1
for(int i=0;i<nEndPos.length-1;i++) &A!KJ.
{ BH0!6Oq
nEndPos = nStartPos[i+1]; F>|9 52
} {F*N=pSq
nEndPos[nEndPos.length-1] = nFileLength; ;Hm'6TR!
} Kn+=lCk
} b`cYpcs
\9)[#Ld
Mj0Cat=
//启动子线程 ?BCyJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MBk"KF
for(int i=0;i<nStartPos.length;i++) ;'RFo?u K
{ {j(4m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eNySJf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &J"YsY
nStartPos,nEndPos,i); c|wCKn}`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EiV=RdL
fileSplitterFetch.start(); j.-VJo)
} RagiV6c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2?i\@r@E|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZcPUtun
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n~z\?Y=*
nEndPos = " + nFileLength); G=M] 8+h
// fileSplitterFetch[nPos.length-1].start(); !awh*Xj6
Oo%!>!Lt,
3 %(Y$8U
//等待子线程结束 EHf)^]Z
//int count = 0; sV0Z
//是否结束while循环 l%"`{
boolean breakWhile = false; <4F7@q,V
;:#U6?=t
c]Unbm^w
while(!bStop) {V2bU}5 [
{ !Cj(A"uqY
write_nPos(); }6~)bLzI}
Utility.sleep(500); M1=_^f=&.
breakWhile = true; zi!#\s^
5]"BRn1*
XK3]AYH
for(int i=0;i<nStartPos.length;i++) <GWR7rUH
{ P!+v:'P5f
if(!fileSplitterFetch.bDownOver) okBE|g
{ gn5% F5W
breakWhile = false; oW'POAr
break; {*=E?oF@
} , p0KLU\-
} *8!w&ME+.
if(breakWhile) A|vP$zy
break; _%IqjJO{=r
rnvQ<671W
NXgRNca
//count++; }z'DWp=uN
//if(count>4) Tx+ p8J|Yr
// siteStop(); 4: sl(r
} {vfq
(L#%!bd
1k>naf~O
System.err.println("文件下载结束！"); gg8c7d:Q
} GJak.,0t
catch(Exception e){e.printStackTrace ();} *C_[jk@6
} 1)U}i ^
F!CAitxd
Dr'sIH^
//获得文件长度 [,7-w
public long getFileSize() ('WY5Yps
{ D9^7m j?e
int nFileLength = -1; Z\!rH"8
try{ *( *z|2
URL url = new URL(siteInfoBean.getSSiteURL()); 7Dl%UG]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <ZrFOb
httpConnection.setRequestProperty("User-Agent","NetFox"); hPPB45^
kME^tpji
*CUdGI&
int responseCode=httpConnection.getResponseCode(); vvh.@f
if(responseCode>=400) ;5M<j3_*
{ b7'F|h^
processErrorCode(responseCode); *]!l%Uf%
return -2; //-2 represent access is error }J;~P 9Y
} iBHw[X,b
t{ H1u
STlPT5e.}
String sHeader; .YiaXP
=jUnM>23
56ZrCr
for(int i=1;;i++) jM\ %$_/
{ DyX0xx^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @KJV1t`
//Utility.log(in.readLine()); ?>)yKa#U
sHeader=httpConnection.getHeaderFieldKey(i); /| f[us-w
if(sHeader!=null) uo 4xnzc
{ ?waebuj>
if(sHeader.equals("Content-Length")) ]^!}*
{ T&4fBMBp,%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j)Lo'&Y~=
break; ;@!;1KDy
} )d_U)b7i
} #01/(:7
else #ko6L3Pi
break; sy.:T]ZH
} cKpQr7]ur
} AY@k-4
catch(IOException e){e.printStackTrace ();} @H4wHlb
catch(Exception e){e.printStackTrace ();} kd`YSkZ
EP0a1.C
OequU'j
Utility.log(nFileLength); C M^r|4K
>Qk97we'9
ER2V*,n@
return nFileLength; ~,G]glu8
} ?1$\pq^
HSql)iT
h/9Sg*k
//保存下载信息（文件指针位置） 9/Wn!Ld
private void write_nPos() hOn
{ h{H]xe[Q
try{ 0/*X=5
output = new DataOutputStream(new FileOutputStream(tmpFile)); q06@SD$
output.writeInt(nStartPos.length); 4%>+Wh[
for(int i=0;i<nStartPos.length;i++) ^@N`e1
{ `=v@i9cTZ
// output.writeLong(nPos); DZ%8 |PmB
output.writeLong(fileSplitterFetch.nStartPos); 5IO3 %p?
output.writeLong(fileSplitterFetch.nEndPos); _;VYFs
} .Map
output.close(); K_FBy
} a^x 0 l
catch(IOException e){e.printStackTrace ();} ja:\W\xhJ
catch(Exception e){e.printStackTrace ();} ME,duY/>Q
} v'$ykZ!Z
uAQg"j
3m~U(yho
//读取保存的下载信息（文件指针位置） (Y>U6
private void read_nPos() ) _#T c
{ |/t K-c6J
try{ rSbQ}O4V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >["Kd.ye
int nCount = input.readInt(); "|\94
nStartPos = new long[nCount]; 3} l;
nEndPos = new long[nCount]; z(r"JNO@
for(int i=0;i<nStartPos.length;i++) [@zkv)D6
{ )Jmw|B
nStartPos = input.readLong(); 8vu2k>
nEndPos = input.readLong(); vo.EM1x
} hOV_Oqe4?
input.close(); eNivlJ,K|@
} ELD +:b
catch(IOException e){e.printStackTrace ();} /T{mS7EpYc
catch(Exception e){e.printStackTrace ();} sbpu qOL
} ruWye1X;
w zdxw$E
VgUvD1v?}
private void processErrorCode(int nErrorCode) hN!.@L
{ k:W=5{[
System.err.println("Error Code : " + nErrorCode); cx<h_
} vDWr|M%``l
DU(X,hDBF
Scf.4~H 0
//停止文件下载 A03I-^0g+
public void siteStop() ;Xz(B4N~o
{ aTi0bQW{
bStop = true; qP@L(_=g
for(int i=0;i<nStartPos.length;i++) ~y`Pwj
fileSplitterFetch.splitterStop(); %jpH:-8'2
%OTQRe:
yM W'-\
} =:kiSrBS3t
} eO~eu]r
//负责部分文件的抓取 D_zcOq9
**FileSplitterFetch.java \gjl^#;
*/ Y{`3`Pg&N
package NetFox; ^9n}-Cqeq
D~XU`;~u
N" 8*FiZ|
import java.io.*; F1zT )wW
import java.net.*; 3@%BA(M
hwc:@'
1mAUEQ!
public class FileSplitterFetch extends Thread { ]Pz|Oi+]
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oXvdR(Sb^
String sURL; //File URL T<!\B]
long nStartPos; //File Snippet Start Position 3{6ps : w
long nEndPos; //File Snippet End Position o$*bm6o
int nThreadID; //Thread's ID f;&` 9s| 1
boolean bDownOver = false; //Downing is over Au~+Zz|mQ
boolean bStop = false; //Stop identical 9T?~$XlX
FileAccessI fileAccessI = null; //File Access interface wA{*W>i
r{bgTG
?L`MFR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jo]m12ps
{ )j$b9ZBk
this.sURL = sURL; &IIJKn|_
this.nStartPos = nStart; D:+)uX}MOf
this.nEndPos = nEnd; S5zpUF=
nThreadID = id; >|y>e{P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F0X5dv
} "v*oga%
Cij$GYkv
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public void run() U]+b`m
{ Krt$=:m|1
while(nStartPos < nEndPos && !bStop) qiF@7i
{ V.O<|tl.
"it`X B.
V,99N'o~x
try{ k^L#,:\&V
URL url = new URL(sURL); GLbc/qs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gsx^j?
httpConnection.setRequestProperty("User-Agent","NetFox"); =vB]*?;9
String sProperty = "bytes="+nStartPos+"-"; 3tJ=d'U
httpConnection.setRequestProperty("RANGE",sProperty); b|\{ !N]
Utility.log(sProperty); a/wUeW
m^W*[^p
~N)( ^ 4
InputStream input = httpConnection.getInputStream(); (MF+/fi
//logResponseHead(httpConnection); KqT#zj
W)G2Cs?p
FN{H\W1cf
byte[] b = new byte[1024]; xkk@{}J\
int nRead; ::^qy^n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <DA{\'jJ
{ w!=_
nStartPos += fileAccessI.write(b,0,nRead); nsM>%+o
//if(nThreadID == 1) ze#rYNvo/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'Qp&,xK
} \}]=?}(
(:</R$I
Y3 Pz00x
Utility.log("Thread " + nThreadID + " is over!"); :pL1F)-*
bDownOver = true; y\r^\ S9%
//nPos = fileAccessI.write (b,0,nRead); a+4`}:KA#
} .b!OZ
catch(Exception e){e.printStackTrace ();} j\i;'t}8g
} ox i a}
} gNMKGf\Y
^?sSsHz
HM(bR"E
//打印回应的头信息 MbT ONt?~v
public void logResponseHead(HttpURLConnection con) kx;xO>dC
{ B` t6H
for(int i=1;;i++) 8gu'dG=
{ 02]8|B(E90
String header=con.getHeaderFieldKey(i); PU]7c2.y
if(header!=null) 5p#o1I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xr7-[)3Q$
Utility.log(header+" : "+con.getHeaderField(header)); 8M".o n
else ue^?/{OuT
break; 42b=z//;
} t?Njw7
} *Dd(+NI
y4)ZUv,}
HlOAo:8'
public void splitterStop() k=ior
{ o}r!qL0c
bStop = true; ~x+:44*
} eE#81]'6a
cAsSN.HFS
S+Yy
} rS,*s'G
j:de}!wc
oJ4mxi@|#
/* ';fU.uy
**FileAccess.java dcrJ,>i}
*//文件访问(定位，写) 0IT20.~
package NetFox; fmZzBZ_
import java.io.*; Q9x` Uy
MZ|c7f&`
gOES2 4$2
public class FileAccessI implements Serializable{ g#9*bF
K\Y6 cj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rH}Dt@
RandomAccessFile oSavedFile; 3LmBV\["
long nPos; n'x`oI)-
XSHwE)m
)P(d66yq'u
public FileAccessI() throws IOException ]VHdE_7)
{ {8>_,z^P)
this("",0); iBPdCp%]`
} bCY^.S-
.eDxIWW+ft
1VPN#Q!
public FileAccessI(String sName,long nPos) throws IOException >FEQtD~F
{ u}@%70A
oSavedFile = new RandomAccessFile(sName,"rw"); c-3YSrY
this.nPos = nPos; -V<=`e
oSavedFile.seek(nPos); =vqE=:X6
} &s6(3k
k{u%p<
]( U%1
public synchronized int write(byte[] b,int nStart,int nLen) oN1wrf}Sh
{ l66ipgw_^I
int n = -1; no\}aTx
try{ ;>QK}#'
oSavedFile.write(b,nStart,nLen); WkU)I2oH
n = nLen; Tr}$Pb1
} 9{]r+z:
catch(IOException e) ay7+H7^|hZ
{ "#eNFCo7k
e.printStackTrace (); W0uM?J\O
} f'zFg["aZS
E#HU?<q8
_>:=<xyOq
return n; }mT%N eS
} aBA#\eV
oRJP5Y5na
(1r>50Ge
} ,[K)E
n9-q5X^e>
zf!\wY"`
/* o"+&^
**SiteInfoBean.java WY.\<$7
*/ l.NkS
package NetFox; {/|8g(
nD?M;XN
$0`$)(Y
public class SiteInfoBean { k~s>8N:&G
/xm} ?t0U
K&gc5L
private String sSiteURL; //Site's URL JXR/K=<^
private String sFilePath; //Saved File's Path L!}j3(I
private String sFileName; //Saved File's Name ?\p%Mx?
private int nSplitter; //Count of Splited Downloading File 2"{]A;@
!A^w6Q;`V
2O)Kn q
public SiteInfoBean() wGQhr="
{//nSplitter的缺省值为5 yfw>y=/p
//default value of nSplitter is 5 RT+30Q?
this("","","",5); hK9oe%kU~
} >J75T1PH=
yOCcp+`T}
4`5Qt=}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E,yzy[gl
{ O t4+VbB6
sSiteURL= sURL; ([XyW{=h!
sFilePath = sPath; "62Ysapq+
sFileName = sName; Go+,jT-
this.nSplitter = nSpiltter; $v}8lBCr3
ThqfZl=V
a!J ow?(
} D(ntVR
Bw/H'Y
/dvnQW4}8
public String getSSiteURL() &+r ;>
{ 6_}){ZR
return sSiteURL; :>-sITeY
} !m O] zn
[F-u'h< *l
>p#d;wK4_
public void setSSiteURL(String value) U@t?jTMBkO
{ 2D_Vo ])l/
sSiteURL = value; tS/APSY
} SIBIh-L
BHBT=,sI
f+88R=-u6S
public String getSFilePath() .$s|T
{ nF y7gA|
return sFilePath; xbH!:R;
} JP% ;rAoJ
g8qAJ4
]=XL9MI
public void setSFilePath(String value) @_:?N(%(
{ AeQ&V d|
sFilePath = value; ,xM*hN3A
} 3'@jRK
>U Ich
g:6}zHK
public String getSFileName() ]X;*\-
{ L5|;VH
return sFileName; D@1^:'$V
} cw-JGqLx
`0vy+T5
[&}<!:9'
public void setSFileName(String value) ;%.k}R%O@
{ 6!PX! UkF
sFileName = value; bIl0rx[`
} ]]QCJf@p
T`0gtSS
{.8)gVBmA
public int getNSplitter() -OGy-"
{ #UnO~IE.m$
return nSplitter; zSufU2
} +A3\Hj&W
szs3x-g
#Lt+6sa]2@
public void setNSplitter(int nCount) -hV KPIb
{ *ww(5 t
nSplitter = nCount; FrM~6A_
} cx%9UK*c
} -r0\
'Bn_'w~j{
:hdh$}y
/* %lW:8ckL
**Utility.java l{x#*~ga
*/ BQmafpp`
package NetFox; pY5HW2TsY|
@uD{`@[
$>37PVVW
public class Utility { !/9Sb1_~
!{aA*E{
<g1hdF0
public Utility() yFtf~8s3
{ T:5%sN;#O
~g|0uO}.
B{7/A[$%C
} 5Jd {Ev
AS^$1i:
//线程睡眠 /3%xQK>%
public static void sleep(int nSecond) ~4gKAD
{ &jd<rs5}
try{ }ZGpd9D
Thread.sleep(nSecond); &8L\FAY0%9
} TTak[e&j3
catch(Exception e) 3Ya6yz
{ 'UCx^-
e.printStackTrace (); Gf.o{
} JU+'UK630
} KftM4SFbK
Pu*UZcXY
//日志 |W];v@b\y
public static void log(String sMsg) X,CFY
{ LMj'?SuH
System.err.println(sMsg); nECf2>Yp v
} N2Hb19/k
tO;W?g
ofv 1G=P
public static void log(int sMsg) %+J*oFwQu
{ S*@0%|Q4r
System.err.println(sMsg); .Sw'Bo!Ee
} =xP{f<`
} .Q@'Ob`
V2skr_1
?E@[~qq_
/* "$YLU}S9
**TestMethod.java =i %w_e
*/ RL8wSK
package NetFox; ?saVk7Z[|5
Ka2tr]+s
SXF_)1QO\W
public class TestMethod { aBLb i
L#bQ`t
ay[*b_f
public TestMethod() GQWTQIl]
{ ///xx/weblogic60b2_win.exe "A3xX&9-q
try{ l_EI7mJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A2S9h,t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1yc@q8
SiteFileFetch fileFetch = new SiteFileFetch(bean); >ON.ftZi
fileFetch.start(); &$im^0`r_
} :N:8O^D^<
catch(Exception e){e.printStackTrace ();} )S?}huX
H.K`#W&
w+P^c|
} F\72^,0
I ^92b
IbwRb
public static void main(String[] args) pSUp"wch
{ VHNiTp
new TestMethod(); rNp#5[e
} X|G+N(`|(
} Ry3 f'gx
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