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)); S[e> 8
} zi_0*znw
for(int i=0;i<nEndPos.length-1;i++) AIG5a$}&
{ gX~lYdA
nEndPos = nStartPos[i+1]; qQwf#&
} }vEMG-sxX
nEndPos[nEndPos.length-1] = nFileLength; FL[,?RU?2
} >aAsUL5W
} tx$`1KA
b?j\YX[e
bo-lT-I
//启动子线程 |Sv}/P-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =eQ'^3a
for(int i=0;i<nStartPos.length;i++) HE:]zH
{ cKB1o0JsYJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ckkm}|&m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ID~}pEQ
nStartPos,nEndPos,i); HP,{/ $i:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4C }#lW9
fileSplitterFetch.start(); gn:&akg
} /[I#3|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J%IKdxa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); owzcc-g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !8*7{7
nEndPos = " + nFileLength); }_oQg_-7e
// fileSplitterFetch[nPos.length-1].start(); 5i-VnG
.|i/ a%J
ig^x%!;
//等待子线程结束 r8Z.}<j
//int count = 0; UmLBoy&*
//是否结束while循环 EvptGM
boolean breakWhile = false; :j`4nXm
X`A+/{ H
:{ Lihe~\
while(!bStop) ^g=j`f[T
{ I`nC\%g
write_nPos(); >W6?!ue_
Utility.sleep(500); skF}_
breakWhile = true; fuT Bh6w&
a(AYY<g
/<k]mY cu
for(int i=0;i<nStartPos.length;i++) m>f8RBp]'
{ +ZR>ul-c
if(!fileSplitterFetch.bDownOver) ojx2[a\
{ ~{ucr#]C
breakWhile = false; FK@Gd)(
break; 1fTf+P
} 6J <.i
} ZU;nXqjc
if(breakWhile) K$wxiGg8P
break; > .K
qb$M.-\ne
$U"pdf
//count++; W)AfXy
//if(count>4) &hJQHlyJM0
// siteStop(); _q}^#-
} K.Y.K$NjP{
]4B&8n!
mM'uRhO+
System.err.println("文件下载结束！"); mZ g'
} C6qGCzlG`
catch(Exception e){e.printStackTrace ();} A+KpECP
} HfEl TC:3f
+o]J0Gu
(gUVZeVFP
//获得文件长度 = O|}R
public long getFileSize() Yv3P]6c.
{ !$p E=~1C
int nFileLength = -1; ft$!u-`
try{ A]MX^eY
URL url = new URL(siteInfoBean.getSSiteURL()); hX:yn:P~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sj&1I.@,>
httpConnection.setRequestProperty("User-Agent","NetFox"); k{ulu
&kQj)
P"|-)d
int responseCode=httpConnection.getResponseCode(); _e "
if(responseCode>=400) '26 ,.1
{ xmejoOF
processErrorCode(responseCode); CUx-k|\
return -2; //-2 represent access is error GQYB2{e>
} 1-.(pA'
i^)JxEPr w
KB$Y8[
String sHeader; mOJ-M@ME
bUe6f,8,
19i=kdH
for(int i=1;;i++) 4$+/7I \
{ _sQhDi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); or(P?Ro
//Utility.log(in.readLine()); qmtH0I7)
sHeader=httpConnection.getHeaderFieldKey(i); Y?%=6S
if(sHeader!=null) f%yNq6l
{ (8(P12l
if(sHeader.equals("Content-Length")) ]+Z,HY@;-
{ >6|Xvtf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sW&h?jdf
break; jpZ 7p;
} |<#yXSi
} hLaQ[9
else F#z1 sl'
break; \^dYmU
} 0U!_o2]
} {Hz;*1?$k
catch(IOException e){e.printStackTrace ();} T3t w.yh
catch(Exception e){e.printStackTrace ();} >:0^v'[
=WK's8FB;8
7!~)a
Utility.log(nFileLength); u6 4{w,
p+CK+m
P}vk5o'
return nFileLength; Ki(0s
} IO"q4(&;P4
G1:"Gxja
ZeH=]G4Zv7
//保存下载信息（文件指针位置） T+>W(w i
private void write_nPos() @Py?.H
{ w}U'>fj
try{ WL;2&S/{@
output = new DataOutputStream(new FileOutputStream(tmpFile)); a[J_H$6H!
output.writeInt(nStartPos.length); `82^!7!
for(int i=0;i<nStartPos.length;i++) "YN6o_*]
{ LAuaowE\v
// output.writeLong(nPos); %Lom#:L'
output.writeLong(fileSplitterFetch.nStartPos); o`nJJ:Cxq-
output.writeLong(fileSplitterFetch.nEndPos); ]3 76F7
} H<
output.close(); :`S\p[5
} 1_>w|6;e
catch(IOException e){e.printStackTrace ();} `~1#X
catch(Exception e){e.printStackTrace ();} *LQt=~
} e09QaY
"sed{?
Bpv"qU7
//读取保存的下载信息（文件指针位置） gH0Rd WX
private void read_nPos() [@0Hmd7
{ EE*FvI`
try{ )H{OqZZYD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;pG5zRe
int nCount = input.readInt(); *s?C\)x
nStartPos = new long[nCount]; yS4nB04`=
nEndPos = new long[nCount]; hmI> 7@&
for(int i=0;i<nStartPos.length;i++) %V92q0XW
{ uCj)7>}v{M
nStartPos = input.readLong(); 2,p= %
nEndPos = input.readLong(); @1V?94T1
} BLb'7`t
input.close(); Ju_(,M-Vgr
} b7HT<$Wg
catch(IOException e){e.printStackTrace ();} UZo[]$"Q`
catch(Exception e){e.printStackTrace ();} 8< z
} @"afEMd
\o5/, C
*a`_,Q{x
private void processErrorCode(int nErrorCode) 3*e )D/lm
{ 21hTun"W
System.err.println("Error Code : " + nErrorCode); pZ 7KWk4
} j^ttTq|l
hne}G._b
~'LoIv20j)
//停止文件下载 l>pnY%(A
public void siteStop() =j8g6#'u
{ uy([>8uu
bStop = true; ,9W!cD+0
for(int i=0;i<nStartPos.length;i++) .19_EQ>+
fileSplitterFetch.splitterStop(); =!=DISPo
D;Y2yc[v
sbV_h;<
} g8]$BhRIfr
} 4qyPjAG
//负责部分文件的抓取 L]=LY
**FileSplitterFetch.java N._^\FRyn
*/ "SpsSQ
package NetFox; 6}:(m#+
VQbKrnX
r:,"k:C
import java.io.*; FwDEYG
import java.net.*; !lI1jb"
<\L=F8[
LF!S`|FF
public class FileSplitterFetch extends Thread { ;RW5XnVx
dDqT#N?Y
Z`ZML+;~6
String sURL; //File URL XpdjWLO]C<
long nStartPos; //File Snippet Start Position V""3#Tw
long nEndPos; //File Snippet End Position SKJ'6*6
int nThreadID; //Thread's ID xsg55`
boolean bDownOver = false; //Downing is over "Wy!,RH
boolean bStop = false; //Stop identical K?=g IC:
FileAccessI fileAccessI = null; //File Access interface 1fV\84m^
oi%IHX(`
?IR+OCAA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LHq*E`
{ t=n@<1d
this.sURL = sURL; f4^\iZ{`G
this.nStartPos = nStart; {QT:1U\.
this.nEndPos = nEnd; s+a#x(7{
nThreadID = id; tS[@?qP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1pTQMf a
} w=ZK=@
5-"aK~@+
j`-9.
public void run() 67wq8|
{ kQ.3J.Q5
while(nStartPos < nEndPos && !bStop) !D9V9p
{ +P=I4-?eX
qhNYQ/uS
/z4n?&tM
try{ 3EyVoS6D
URL url = new URL(sURL); m"vWu0/#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uD4$<rSHb
httpConnection.setRequestProperty("User-Agent","NetFox"); :BUr8%l
String sProperty = "bytes="+nStartPos+"-"; ExSy/^4f
httpConnection.setRequestProperty("RANGE",sProperty); _@sSVh$+
Utility.log(sProperty); 27UnH: =
%kiPE<<x
7/FF}d
InputStream input = httpConnection.getInputStream(); :qvaI,
//logResponseHead(httpConnection); 8o,"G}Hjk
zl$z>z)
ksQw|>K
byte[] b = new byte[1024]; SoB6F9
int nRead; :Q>{Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x-SYfvYY
{ I(+%`{Wv
nStartPos += fileAccessI.write(b,0,nRead); 3E;<aCG?
//if(nThreadID == 1) %F]:nk`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7niI65
} -to3I
"XKd#ncP
kj!mgu#T
Utility.log("Thread " + nThreadID + " is over!"); TL([hR _
bDownOver = true; 3@mW/l>X
//nPos = fileAccessI.write (b,0,nRead); d0-T\\U
} iuEQ?fp
catch(Exception e){e.printStackTrace ();} rq^VOK|L
} mA6Nmq%{ F
} incUa;
iIU>:)i
$%5!CD1)
//打印回应的头信息 DZV U!J
public void logResponseHead(HttpURLConnection con) oqy}?<SQ
{ Q5tx\GE
for(int i=1;;i++) e`Tssa+
{ <O]B'Wc [
String header=con.getHeaderFieldKey(i); =kn-F T
if(header!=null) \>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /@]@Tz@'
Utility.log(header+" : "+con.getHeaderField(header)); P6;Cohfh
else p}h9>R
break; rTM0[2N
} YMn_9s7<
} ;r3|EA35
\_3#%%z
A]OVmw
public void splitterStop() xu*dPG)v
{ "$|ne[b2
bStop = true; /w:~!3Aj0+
} SgY\h{{sP
q@Sj$
yx/.4DW1Ua
} 2R`}}4<Z
s%t =*+L\
9E]7Etfw
/* NU!B|l
**FileAccess.java O:W4W=K
*//文件访问(定位，写) d# q8-
package NetFox; &BQ%df<y\
import java.io.*; LArfX,x3i
TS;?>J-
`r.
public class FileAccessI implements Serializable{ Mt+ggF.
\FjY;rqfKe
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3ypf_]<
RandomAccessFile oSavedFile; firiYL"=44
long nPos; Be2yS]U
BI0 A0
Qb&gKQtt@
public FileAccessI() throws IOException F[==vte|
{ +v"%@lC};
this("",0); q<wQ/m
} 1<3!
=j S
!gFUC<4bu
public FileAccessI(String sName,long nPos) throws IOException kIYV%O
{ 2^=.jML[
oSavedFile = new RandomAccessFile(sName,"rw"); nAW`G'V#
this.nPos = nPos; ]LZ,>v
oSavedFile.seek(nPos); I xE}v%&
} ~QE-$;
:*s+X$x,<
kK$*,]iCp
public synchronized int write(byte[] b,int nStart,int nLen) y,=TB[d#
{ D``>1IA]
int n = -1; O,?aVgY
try{ -WK
oSavedFile.write(b,nStart,nLen); g'1ASMuR
n = nLen; \9s x_T
} RaLc}F)9
catch(IOException e) 6T{SRN{
{ z+%74O"c
e.printStackTrace (); 2Jc9}|,
} RT+_e
5mB'\xGO2
z7um9g
return n; $|r p5D6
} !x1ivP
s+XDtO
hZNAI
} APT/z0X>
2x dN0S
f/RDo4
/* "N*i!h
**SiteInfoBean.java ad[oor/7|
*/ V-TWC@Y"
package NetFox; ]~-vU{
,Frdi>7 ~
)m[dfeqd +
public class SiteInfoBean { "=\@ a=
5RhP^:i@C
D!CuE7}
private String sSiteURL; //Site's URL 1rQKHC:|
private String sFilePath; //Saved File's Path S K7b]J>
private String sFileName; //Saved File's Name 'or8CGr^p
private int nSplitter; //Count of Splited Downloading File !`EhVV8u-_
C#4/~+
caC(KK#<
public SiteInfoBean() [p[C45d=<
{//nSplitter的缺省值为5 gtV*`g
//default value of nSplitter is 5 3&z.m/
this("","","",5); rE&+fSBD
} >*cg K}!@
JW-!m8
5D%gDw+"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A%c)=(,
{ qmM%MPv
sSiteURL= sURL; wx%TQ!
sFilePath = sPath; ;l>C[6]
sFileName = sName; W^AY:#eX~Q
this.nSplitter = nSpiltter; \w+a Q?e_
nH% 1lD?:
y OLqIvN
} BbdJR]N/!h
&i%1\o
"ZLujpZcG
public String getSSiteURL() +1j+%&).
{ njN]0l{p
return sSiteURL; /l@h[}g+d-
} 2>!?EIE7
EU"J'?
Y94/tjt
public void setSSiteURL(String value) &33.mdBH
{ nlkQ'XGAI
sSiteURL = value; eq#x~O4
} wz(D }N5
~M4@hG!
uepL"%.@7|
public String getSFilePath() ,dO$R.h
{ )mbRG9P
return sFilePath; XU19+mW=P
} :u$+lq
XTOZ]H*^
x3++JG
public void setSFilePath(String value) bR;Zc
{ +)gXU Vwd
sFilePath = value; gYy9N=f+
} /P3s.-sL
Pqm)OZE?
}lzN)e
public String getSFileName() ]9}T)Df'
{ `bF]O"
return sFileName; OnKPD=<
} AZTn!hrU
_p`@/[(|
^,M&PP6
public void setSFileName(String value) &G"r>,HU
{ &RP}w%I1
sFileName = value; \1p5$0z
} q T pvz
{UR&Y
J|BZ{T}d
public int getNSplitter() VF<C#I
{ 6(X5n5C
return nSplitter; >.-$?2
} t9Nu4yl
*(4TasQu
Y/1,%8n
public void setNSplitter(int nCount) &PAgab2$
{ %VCfcM}5I
nSplitter = nCount; 1xkU;no
} 2%DleR'i
} gxku3<S
EdPN=
F|DKp[<]8
/* ]U,K]y[Bj
**Utility.java oe5.tkc
*/ h1 D#,
package NetFox; (BA2
gAY%VFBP0
dTV:/QM
public class Utility { K~#wvUb
`=0J:
~',}]_'oR-
public Utility() I'[hvp
{ z]YP
-*K!JC-
`>q|_w\e
} B~u_zZE
s\`Vr;R:|
//线程睡眠 |;-,(509
public static void sleep(int nSecond) jbHk
{ v^lR]9;
try{ `tkd1M
Thread.sleep(nSecond); WR*|kh
} Hhbf9)
catch(Exception e) ikGH:{
{ yMNLsR~rh
e.printStackTrace (); ,Dz2cR6
} x,Cc$C~YP
} 4R U1tWQ%
8O]U&A@
//日志 4nhe *ip
public static void log(String sMsg) #&1Y!kbdd
{ LaE;{jY
System.err.println(sMsg); mF>CH]k3
} FNDLqf!j
sQA{[l!aj
Zw5\{Z0
public static void log(int sMsg) LC/w".oq?
{ ;!@\|E
System.err.println(sMsg); t#y
} (/_Q r2KfC
} P#H#@:/3
gKZ{O
|<.b:e\4
/* {/BEO=8q2
**TestMethod.java R0<ka[+
*/ n;"4`6L~
package NetFox; z#!xqIg0
7[-jr;v
v.1= TBh
public class TestMethod { xLZQ\2q
lxK_+fj q
yvxC/Jo4
public TestMethod() \2<2&=h?
{ ///xx/weblogic60b2_win.exe ISr~JQr
try{ r1FE$R~C=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F.=uJdl.!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LeW.uh3.
SiteFileFetch fileFetch = new SiteFileFetch(bean); e![Q1!r
fileFetch.start(); lq@Vb{Z
} {K'SOhH4?
catch(Exception e){e.printStackTrace ();} 8mA6l0
F$ .j|C1a
$UjSP
} ,l<-*yMD
F!>K8q
1#qCD["8
public static void main(String[] args) LM'` U-/e$
{ +29;T0>a
new TestMethod(); T , =ga
} Za!c=(5
} DuvP3(K
点击下载更多相关资料