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)); \*$^}8
} >]h{[kU %4
for(int i=0;i<nEndPos.length-1;i++) hi8q?4jE
{ ;+hh|NiQ
nEndPos = nStartPos[i+1]; %SmOP sz
} Cj0r2^`
nEndPos[nEndPos.length-1] = nFileLength; ^j<v~GTx+
} ,->ihxf
} {T4_Xn-I
qed_PsI
7 Lm9I
//启动子线程 :5k* kx#y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Sy8t2lk
for(int i=0;i<nStartPos.length;i++) =3bk=vy
{ ;8]HCC@:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s%jBIeh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EG{+Sz
nStartPos,nEndPos,i); n`5Nf
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wmbc `XC
fileSplitterFetch.start(); w S
} q<09]i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j\uZo.Ot+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jX7K-L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", # &v4c
nEndPos = " + nFileLength); c9|4[_&B~
// fileSplitterFetch[nPos.length-1].start(); i2qN 0?n
[c?0Q3F
'}hSh
//等待子线程结束 \RDN_Z
//int count = 0; u3h(EAH>
//是否结束while循环 g0,~|.
boolean breakWhile = false; 7Jb&~{DVk
$[T~<I
$JFjR@j
while(!bStop) 2Io|?
{ 0)dpU1B#M
write_nPos(); (TeH)j!
Utility.sleep(500); (PpY*jKR
breakWhile = true; x?Sx cQP
aCU[9Xr?
+Y?Tri
for(int i=0;i<nStartPos.length;i++) -h8mJ D%Oi
{ )q$[uS_1[
if(!fileSplitterFetch.bDownOver) 4phCn5
{ QytO0K5
breakWhile = false; :DH@zR
break; yCjc5d|tT
} e#}t am
} 2f(`HSC'
if(breakWhile) f}c;s
break; ?O25k!7
LW=qX%o{
=9&2udV1
//count++; JQ+Mg&&Q
//if(count>4) 48p3m)5
// siteStop(); e{8C0=
} V FM[-
?c.\\2>|F
o#FctM'Z
System.err.println("文件下载结束！"); #hBqgG:>
} #c|l|Xvq2
catch(Exception e){e.printStackTrace ();} ,.Gp_BI
} ir^d7CV,
'bfxQ76@sa
i}T*| P
//获得文件长度 5zS%F: 3
public long getFileSize() M.g2y&8
{ DS8HSSD
int nFileLength = -1; 2?,lr2
try{ dwn|1%D
URL url = new URL(siteInfoBean.getSSiteURL()); r,eH7&P9{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q;SD+%tI
httpConnection.setRequestProperty("User-Agent","NetFox"); t_/qd9Jv
o9sQ!gptw
wo9R:kQ
int responseCode=httpConnection.getResponseCode(); 3r%v@8)!b
if(responseCode>=400) 9No6\{[M
{ n[/D>Pi
processErrorCode(responseCode); l"8g9z
return -2; //-2 represent access is error 88u[s@
} thPAD+u.3
t(}Y/'
9ERdjS
String sHeader; 5T/+pC$e=
{Lju7'5L
3\2&?VAjR
for(int i=1;;i++) ;)rhx`"n
{ z{R Mb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ejg!1*H@n
//Utility.log(in.readLine()); 8h ol4'B
sHeader=httpConnection.getHeaderFieldKey(i); 0,0WdJAe
if(sHeader!=null) y1`%3\
{ `y'%dY}$n
if(sHeader.equals("Content-Length")) 3B#fnj
{ 9Zx| L/\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *r>Y]VG;S
break; 1drg5
} K`=U5vG^
} q4:zr
else "4XjABJ4'
break; !@V]H
} #cR5k@
} 41R~.?
catch(IOException e){e.printStackTrace ();} X>dQK4!R
catch(Exception e){e.printStackTrace ();} 2Jo|P A`9
, wk}[MF
n(A;:)W{
Utility.log(nFileLength); +46& Zb35
i% 0qN
b?k,_;\
return nFileLength; ca &zYXy
} ^cdbM
&IQNsJL!e
r0z8?
//保存下载信息（文件指针位置） .yDR2sW
private void write_nPos() ^Oj^7.T+
{ 6heK8*.T
try{ i?>>%juK
output = new DataOutputStream(new FileOutputStream(tmpFile)); &*Z)[Bl
output.writeInt(nStartPos.length); uvDOTRf
for(int i=0;i<nStartPos.length;i++) *o=Z~U9z
{ o<|u4r={s
// output.writeLong(nPos); T&dc)t`o
output.writeLong(fileSplitterFetch.nStartPos); *`s*l+0b
output.writeLong(fileSplitterFetch.nEndPos); KjA7x
} w^~s4Q_>>
output.close(); ,*$Y[UT
} m%U=:u7#M
catch(IOException e){e.printStackTrace ();} .:-*89c
catch(Exception e){e.printStackTrace ();} i39_( )X
} k]4CN
i[/1AI
|}l/6WHB
//读取保存的下载信息（文件指针位置） SOD3MsAK
private void read_nPos() Kd}%%L
{ M7DoAS{6e
try{ vSQB~Vw8t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H1evW
int nCount = input.readInt(); MNfc1I_#
nStartPos = new long[nCount]; g6q[ I8
nEndPos = new long[nCount]; j1JdG<n
for(int i=0;i<nStartPos.length;i++) \KEmfCx'n
{ r*7J#M /
nStartPos = input.readLong(); SM}& @cJ
nEndPos = input.readLong(); H2_6m5[&,
} j"0TAYmXwu
input.close(); c:DV8'fT
} <95*z @
catch(IOException e){e.printStackTrace ();} +C$wkx]
catch(Exception e){e.printStackTrace ();} ZU:c[`
} AWZ4h,as{
4YMUkwh
R<T5lkJ\/
private void processErrorCode(int nErrorCode) <SRSJJR|(
{ Ze`ms96j{
System.err.println("Error Code : " + nErrorCode); pfk)_;>,
} kDKfJp&a
s4 Uk5<
Si;eBPFH
//停止文件下载 kKQD$g.z6
public void siteStop() %e: hVU
{ l)Cg?9
bStop = true; QswFISch
for(int i=0;i<nStartPos.length;i++) o`jVd,aj
fileSplitterFetch.splitterStop(); K`R
R*"zLJP
S?H qrf7<
} Yu9(qRK
} e58tf3
//负责部分文件的抓取 $+ \JT/eG9
**FileSplitterFetch.java ;;17 #T2
*/ ds+0y;vc
package NetFox; =sXk,I;
e=6C0fr
uQkFFWS
import java.io.*; 0Q/BTT%X
import java.net.*; S#D6mg$Z,
JOq&(AZe
dqL)q3
public class FileSplitterFetch extends Thread { i;<H^\%
yzCamm4~0
o 3 G*
String sURL; //File URL :2&W9v
long nStartPos; //File Snippet Start Position 4H%Ai(F}_
long nEndPos; //File Snippet End Position _nW#Cl~
int nThreadID; //Thread's ID k5Df97\s
boolean bDownOver = false; //Downing is over {Pi]i?
boolean bStop = false; //Stop identical alQ:'K
FileAccessI fileAccessI = null; //File Access interface (d5kD#.N
7OZjLD{ID
Y&b JKX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a/ Z\h{*
{ i\P)P!
this.sURL = sURL; rcMSso2
this.nStartPos = nStart; f,Dj@?3+
this.nEndPos = nEnd; _$qH\>se
nThreadID = id; LT '2446
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?F%,d{^
} #.W<[KZf
8<g9 ~L
G C3G=DTt
public void run() tsTCZ);(
{ =qTmFszT
while(nStartPos < nEndPos && !bStop) dxeLu
{ >uDE<MUC
Bt-2S,c,o
TzY[-YlvF
try{ !.5,RIf
URL url = new URL(sURL); 4T:@W C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e/!xyd
httpConnection.setRequestProperty("User-Agent","NetFox"); eN]9=Y~-K
String sProperty = "bytes="+nStartPos+"-"; w'D=K_h
httpConnection.setRequestProperty("RANGE",sProperty); 64-;| k4F
Utility.log(sProperty); p#(5 ;
nJo6;_MI!
6<C|O-
InputStream input = httpConnection.getInputStream(); _QOZ`st
//logResponseHead(httpConnection); t2q{;d~.
Dj@7vM%_
r5aOQ
byte[] b = new byte[1024]; r5\|%5=J
int nRead; ZncJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /aD3E"Op
{ >FM2T<.;
nStartPos += fileAccessI.write(b,0,nRead); a{7'qmN1
//if(nThreadID == 1) q*4=sf,>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1$ C\`
} \B~}s}
?T <2Cl'C
u IGeSd5B
Utility.log("Thread " + nThreadID + " is over!"); dBMr%6tz
bDownOver = true; r5g:#mF"
//nPos = fileAccessI.write (b,0,nRead); #Rcb iV*M
} Ves x$!F#
catch(Exception e){e.printStackTrace ();} jpek=4E
} P+nd?:cz
} [oh0 )wzB
E#m|Sq
RW04>oxVn
//打印回应的头信息 wm/=]*jpK
public void logResponseHead(HttpURLConnection con) h"DxgG
{ 1x~dsM;q
for(int i=1;;i++) &;Jg2f%.
{ <^8&2wAkJ
String header=con.getHeaderFieldKey(i); GY,HEe]2r
if(header!=null) &!5S'J%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Sr?2~R0&
Utility.log(header+" : "+con.getHeaderField(header)); *Z,?VEO
else NvqIYW
break; \_J;i[
} a8laPN
} 1z$K54Mj
P4S]bPIp
YZ0Jei8+-
public void splitterStop() E2~&GkU.UN
{ (W4H?u@X0
bStop = true; m]#oZVngy
} Tweku}D7
w5uOkz #
2Ub!wee
} ,4tuWO)"
!O}^Y
a08`h.dyN
/* V 0M&D,
**FileAccess.java V*1hoC#
*//文件访问(定位，写) aBonq]W
package NetFox; .>Fy ]Cqoh
import java.io.*; r0fxEYze&
yO`HL'SMo
oi:!YVc
public class FileAccessI implements Serializable{ 6wY6*R
)eaEc9o>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :sL?jGk\
RandomAccessFile oSavedFile; 4V9S~^v|
long nPos; 5:sk&0:@U
$)6%LG_@
Hlj_oDL
public FileAccessI() throws IOException U+FI^Xrt#
{ _8I\!
this("",0); M4`.[P4
} o1zKns?
mW&hUPRx
z[~ph/^
public FileAccessI(String sName,long nPos) throws IOException gJC~$/2
{ -L&%,%
oSavedFile = new RandomAccessFile(sName,"rw"); (AI 4a+
this.nPos = nPos; iu+r=sp
oSavedFile.seek(nPos); z+(V2?xcvt
} J70r`
|b'}.(/3i
rZSD)I
public synchronized int write(byte[] b,int nStart,int nLen) 0c6Ea>S[
{ 8.m9 =+)8
int n = -1; ]w;!x7bU(
try{ 9 m`VIB
oSavedFile.write(b,nStart,nLen); ]]^eIjg>a6
n = nLen; 6k-
} 'BOMFp7c
catch(IOException e) bc}BQ|Q
{ 2Mo oqJp
e.printStackTrace (); O; #qG/b1
} Hru~Y}V
r(6$.zx
a 0+W-#G
return n; D@ 4sq^|2
} B9h'}460H
2{;~Bgd
s5cY>
} %;MM+xVVX
f5o##ia7:
cy @",z
/* %-J}m
**SiteInfoBean.java ;:A/WU.^
*/ )N'rYS'9
package NetFox; sRKoM
k|D =Q
,|G~PC8
public class SiteInfoBean { >o,l/#z
1 ` ={**
VteMsL/H
private String sSiteURL; //Site's URL N,ysv/zq7
private String sFilePath; //Saved File's Path Oz-;2
private String sFileName; //Saved File's Name 6h9Hf$'
private int nSplitter; //Count of Splited Downloading File 3EO:Uk5<
%&}gt+L(M
fZka$ 4
public SiteInfoBean() vMv? fE"
{//nSplitter的缺省值为5 k!)Pl,nJ
//default value of nSplitter is 5 'D&[Y)f^
this("","","",5); |B~^7RHXo
} .hVB)@/
Xn=
f{+n$Cos
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~U$ioQy<
{ O~DdMW
sSiteURL= sURL; 6O\a\z
sFilePath = sPath; h"ZR`?h
sFileName = sName; L)yc_ d5
this.nSplitter = nSpiltter; @tzL4hy%^j
caD)'FSES
+Jw+rjnP
} Tx:S{n7&
]gjB%R[.m
EAZLo;
public String getSSiteURL() Z%$tV3a?
{ fb|%)A=
return sSiteURL; /0z#0gNp
} y*H rv
HVH<S
7v]9) W=y
public void setSSiteURL(String value) hZwJ@ Vm#
{ %Rm`+
sSiteURL = value; !cNw8"SIU
} 1)v]<Ga~%1
B x-"<^<
zTS P8Q7
public String getSFilePath() hmp!|Q[)
{ *iiyU}x
return sFilePath; %@'[g]hk
} HA`qU
_>RTefL5
4RL0@)0F
public void setSFilePath(String value) |] cFsB#G
{ D*}_L
sFilePath = value; iTcq=
} [Ufx=BPx3
}UX0 eI4
|f{(MMlj
public String getSFileName() T%O2=h\} E
{ fVo7wp
return sFileName; bvF-F$n%F
} t .-%@,s
R q9(<'F
,-`A6ehg
public void setSFileName(String value) ^^(!>n6r^
{ d*R('0z{
sFileName = value; /zg|I?$>Z4
} L['g')g.
*_@t$W
Ex-?[Hq
public int getNSplitter() iCIU'yI
{ Ye]-RN/W
return nSplitter; [yx8?5
} %_. fEFy07
@FaK/lKK
k7)<3f3&S.
public void setNSplitter(int nCount) 0P l>k'9
{ 7p_B?r
nSplitter = nCount; ^,{ r[}
} 3A!Qu$r9
} R "qt}4m
H6Q!~o\"H
K+3+?oYKH
/* }e]tn)
**Utility.java "@(Sw>*o
*/ \\Te\l|L
package NetFox; WwF2Ry^a
cI (}
Wxa</n8S[n
public class Utility { Nq"J[l*+g
%`\=qSf*
Wa<SYJ
public Utility() Lk2;\D>
{ "U|u-ka8B
bY}:!aR<mK
bj,cU)t0
} -9;XNp
bBY7^k
//线程睡眠 Aa}Nr5{O|
public static void sleep(int nSecond) k]=lo'bF4
{ =^mBj?(V7
try{ :!L>_ f
Thread.sleep(nSecond); 7bYN
} l?O%yf`s
catch(Exception e) )7 M
{ tQ,3nI!|xF
e.printStackTrace (); gt\*9P
} tvcM< e20
} D]?yGI_
F*p@hl
//日志 mWTV)z57
public static void log(String sMsg) dmPAPCm%y
{ s|D[_N!|
System.err.println(sMsg); UId?a}J
} ?)2;W
$Gs|Z$(
cv"Bhql
public static void log(int sMsg) JQDS3v=1$
{ go?}M]c%7
System.err.println(sMsg); NeR1}W
} N) '|l0x0
} b8&z~'ieR
?/}-&A"
_rz7)%Y'#$
/* Odr<fvV,>
**TestMethod.java mbXW$E-&R2
*/ qo7jrY5G
package NetFox; 6r)B|~,OA
yX%NFXD
Oid;s!-S6
public class TestMethod { t/J|<Ooj?
O{Y*a )"
o#hFK'&~
public TestMethod() >0S(se$
{ ///xx/weblogic60b2_win.exe Le2rc*T
try{ ;N^4R$Q.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^?S lM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); thSXri?kl
SiteFileFetch fileFetch = new SiteFileFetch(bean); YP73
fileFetch.start(); FW:V<{f
} ."j=s#OC(
catch(Exception e){e.printStackTrace ();} ]SUW"5L-
DHVfb(H5e
#:8V<rc^
} o3Z<tI8-V
:czUOZ_
,U.|+i{
public static void main(String[] args) <~ ?LU^
{ 4F,RlKHBl
new TestMethod(); UV\&9>@L
} HXgf=R/$
} z6Zd/mt~x
点击下载更多相关资料