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)); )U$]J*LI
} !}[cY76_
for(int i=0;i<nEndPos.length-1;i++) ~sk{O%OI
{ O:^m#:[cE
nEndPos = nStartPos[i+1]; YY? }/r
} !X 8<;e}2
nEndPos[nEndPos.length-1] = nFileLength; ;R#:? r;t
} <;T$?J9
} {\87]xJ
M?yWFqFt9m
? FlV<nE"J
//启动子线程 h_w_OCC&2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;Xzay|
for(int i=0;i<nStartPos.length;i++) oJ<Wh @
{ ?M02|8-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UN,y/V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y$L>tFA
nStartPos,nEndPos,i); @1p,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,vN0Jpf}\8
fileSplitterFetch.start(); \q |n0>
} c2$&pZ M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A&dNCB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MZ/PXY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `U~Y{f_!H
nEndPos = " + nFileLength); $AI0&#NM
// fileSplitterFetch[nPos.length-1].start(); bM%c*_$F7
lMcSe8LBQa
vW\|% @hW,
//等待子线程结束 W@:a3RJ
//int count = 0; K9BoIHo
//是否结束while循环 TAXl73j_CY
boolean breakWhile = false; 5[1#d\QR
0xNlO9b/
`6t3D&.u0
while(!bStop) 1|PmZPKq9n
{ /nX+*L}d/
write_nPos(); |>Xw"]b;
Utility.sleep(500); TYs#v/)I
breakWhile = true; REmD*gf
cuw3}4m%
OR\-%JX/5
for(int i=0;i<nStartPos.length;i++) wG&+*,}
{ HOb-q|w
if(!fileSplitterFetch.bDownOver) uy,ySBY
{ A{7N#-h_
breakWhile = false; ~6hG"t]:
break; 5xEk 7g.
} iN}BMd.U
} TF@HwF"#
if(breakWhile) {]a 6o[}u
break; R+s_uwS
JKFV7{%Gl
? 77ye
//count++; @c8s<9I]
//if(count>4) SwDUg}M~
// siteStop(); {mlJE>~%
} `tCOe
? }k~>. \
yk5T"#'+
System.err.println("文件下载结束！"); }UzO_&Z#6
} ,u,]ab
catch(Exception e){e.printStackTrace ();} cZ" Ut
} 's]+.3">L1
B) 81mcy
\I\'c.$I.Y
//获得文件长度 @QAyXwp
public long getFileSize() aE_)iE|
{ `R}D@
int nFileLength = -1; +njE
try{ oadlyqlw#
URL url = new URL(siteInfoBean.getSSiteURL()); =](c7HEQf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !n`ogzOh
httpConnection.setRequestProperty("User-Agent","NetFox"); jH*+\:UP-
Z{ntF
Cf_Ik
int responseCode=httpConnection.getResponseCode(); PAe2hJ
if(responseCode>=400) #"M 'Cs
{ C/P,W>8
processErrorCode(responseCode); {C%/>e2-%
return -2; //-2 represent access is error S|A?z)I
} %@!Vx
4*UoTE-g$
{PM)D [$i
String sHeader; l|-TGjsX
X7sWu{n
>4d2IO1\
for(int i=1;;i++) MwxfTH"wi
{ Q<L.!%vu}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,EgIH%*g
//Utility.log(in.readLine()); {-rK:*yP'u
sHeader=httpConnection.getHeaderFieldKey(i); ];P^q`n=.
if(sHeader!=null) Ih}I`wY-
{ o8P 5C4y
if(sHeader.equals("Content-Length")) hfY Ieb#91
{ ? OBe!NDf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^i{B8]2,
break; %J`;
} xDBEs*
} S,5>g07-`
else ^uW!=%D
break; qYFol#=%
} ?ng?>!
} 7"f$;CN?~
catch(IOException e){e.printStackTrace ();} y+RT[*bX5o
catch(Exception e){e.printStackTrace ();} VI%879Z\e
/Q"nQSG
s)HbBt-
Utility.log(nFileLength); o'Q)V
F9e$2J)C
W%09.bF
return nFileLength; r^P}xGGK
} "F+ 9xf&r
0k5Zl?
xPh%?j?*v
//保存下载信息（文件指针位置） 66=6;77
private void write_nPos() E{r_CR+8
{ ,_T,B'a:
try{ A.vcE
output = new DataOutputStream(new FileOutputStream(tmpFile)); {KL<Hx2M
output.writeInt(nStartPos.length); &Ko}Pv
for(int i=0;i<nStartPos.length;i++) RR:m<9l
{ [pbX_
// output.writeLong(nPos); T\:3(+uK
output.writeLong(fileSplitterFetch.nStartPos); CF^7 {g(y_
output.writeLong(fileSplitterFetch.nEndPos); -8tWc]c |4
} l)z15e5X
output.close(); Q8M&nf
} %^"Tz,f
catch(IOException e){e.printStackTrace ();} IxCEE5+`%
catch(Exception e){e.printStackTrace ();} t4?g_$>
} lN+NhPF
(FMYR8H*(
kq:,}fc;B
//读取保存的下载信息（文件指针位置） 9B'l+nP
private void read_nPos() b]s=Uv#)
{ mW 5L;>
try{ w;' F;j~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %_1~z[Dv
int nCount = input.readInt(); /-$`GT?l
nStartPos = new long[nCount]; j:|60hDz^
nEndPos = new long[nCount]; mf@YmKbp
for(int i=0;i<nStartPos.length;i++) UL[4sv6\9
{ ~`hI|i<]
nStartPos = input.readLong(); R*TCoEKO
nEndPos = input.readLong(); =rgWOn8
} #'<I!G
input.close(); )+ Wr- Yay
} 1l\O9D +$
catch(IOException e){e.printStackTrace ();} nl5K1!1
catch(Exception e){e.printStackTrace ();} j&fr4t3
} |1 is!leP
-baGr;,Cu
,-c(D-&
private void processErrorCode(int nErrorCode) ;0xCrE{l"
{ SBjtg@:G0n
System.err.println("Error Code : " + nErrorCode); HtEjM|zj
} $7)O&T*q'
ER5Q` H
9;Wz;p
//停止文件下载 qB]z"Hfq,
public void siteStop() 1elcP`N1
{ FTCp3g
bStop = true; GQ|kcY=
for(int i=0;i<nStartPos.length;i++) w}NgFrL
fileSplitterFetch.splitterStop(); N,'JQch},8
<4{@g]0RV
h%+8}uywZ
} u{H,i(mx?
} M=o,Sav5*
//负责部分文件的抓取 PBn(k>=+
**FileSplitterFetch.java 0 nWV1)Q0=
*/ B[4y(Im
package NetFox; ; tvB{s_
J~gfMp.
h,140pW
import java.io.*; tt J,rM
import java.net.*; &%qD Som3
{K3\S 0L
#yr19i ?
public class FileSplitterFetch extends Thread { tx5_e[
mkE*.I0=
aE#ZTc=
String sURL; //File URL Q=PaTh
long nStartPos; //File Snippet Start Position U"m!f*a
long nEndPos; //File Snippet End Position kP;:s
int nThreadID; //Thread's ID (= !_5l
boolean bDownOver = false; //Downing is over XZ|"7as
boolean bStop = false; //Stop identical f!LZT!y
FileAccessI fileAccessI = null; //File Access interface crgYr$@s?
[b#jw,7
b1[U9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5)$U<^uy
{ /=e[(5X|O
this.sURL = sURL; sWavxh8A
this.nStartPos = nStart; ziH2<@
this.nEndPos = nEnd; j~Gu;%tq
nThreadID = id; bq(*r:`"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g=U?{<8.m
} X'?v8\mPK
&2xYG{Z
Jh466; E
public void run() [0&Lvx
{ &/JnAfmYqt
while(nStartPos < nEndPos && !bStop) }(o/+H4
{ GV[%P
_L$)~},cT
=r-Wy.a@
try{ 3gabk/
URL url = new URL(sURL); W^=89I4]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $\^]MxI
httpConnection.setRequestProperty("User-Agent","NetFox"); V'mpl
String sProperty = "bytes="+nStartPos+"-"; 2{V|
httpConnection.setRequestProperty("RANGE",sProperty); e#nTp b
Utility.log(sProperty); 3&y u
3@"VS_;?
iL,3g[g
InputStream input = httpConnection.getInputStream(); ItaJgtsV
//logResponseHead(httpConnection); B:mlBSH
<BU|?T6~
'h= >ej*
byte[] b = new byte[1024]; q!ZmF1sU
int nRead; ]#:xl}'LS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w x,;
{ 1|. 0]~0
nStartPos += fileAccessI.write(b,0,nRead); r?X^*o9
//if(nThreadID == 1) /Hx0=I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w`7l;7[
} c=b\9!hr_E
^_=0.:QaW
GUp51*#XR
Utility.log("Thread " + nThreadID + " is over!"); "mH^Owai
bDownOver = true; CqX%V":2
//nPos = fileAccessI.write (b,0,nRead); aZ0H)
} \!^o<$s.G
catch(Exception e){e.printStackTrace ();} Aj`4uFhiL
} C|lMXp\*
} unX^MPpw
A&M/W'$s
>u/yp[Ky
//打印回应的头信息 (w^&NU'e
public void logResponseHead(HttpURLConnection con) `q@~78`
{ EV(/@kN2
for(int i=1;;i++) /Z@.;M
{ cq=R
String header=con.getHeaderFieldKey(i); 4dok/ +Ec
if(header!=null) Qdn:4yk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -qEr-[z
Utility.log(header+" : "+con.getHeaderField(header)); _0f[.vN
else <n:?WP~U
break; \c\=S
} ueg X
} iB,*X[}EqG
U^YPL,m1
e=R} 4`
public void splitterStop() dog,vUu
{ 7,4x7!
bStop = true; Rd$<R
} <'B^z0I,
c"$_V[m
-)Vj08aP
} [<`+9R
Aa Ma9hvT!
0x &^{P~
/* 'oEmbk8Hg
**FileAccess.java $+);!?^|:
*//文件访问(定位，写) >@%!r
package NetFox; x('yBf
import java.io.*; l^"G\ZVI
8(I"C$D!k
FV9RrI2
public class FileAccessI implements Serializable{ BxqCV%9o
xV6j6k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hf-S6PEsM
RandomAccessFile oSavedFile; ,]Ma,2
long nPos; dkLR Q
*,pqpD>
h`Mf;'P
public FileAccessI() throws IOException p(8\w-6
{ :Rn9rdX
this("",0); ;uDFd04w [
} ?`XKaD! f
&Xav$6+Z1J
Ll`apKr
public FileAccessI(String sName,long nPos) throws IOException $d=lDN
{ zW _'sC
oSavedFile = new RandomAccessFile(sName,"rw"); YH>n{o;- ?
this.nPos = nPos; FN R& :
oSavedFile.seek(nPos); gkdjH8(2
} o(zg_!P
L}mhMxOTi
x9e 9$ww}
public synchronized int write(byte[] b,int nStart,int nLen) vKC>t95
{ 4kM<L}J#
int n = -1; 'yNp J'
try{ GND[f}
oSavedFile.write(b,nStart,nLen); g;h&Xkp
n = nLen; 9T1G/0k-
} 6>Cubb>
catch(IOException e) t|m3b~Oyv
{ r:cUAe7#
e.printStackTrace (); 4HJrR^
} Qi61(lK
3C2>
&M!:,B
return n; "mf;k^sqS
} Xy{+=UY
uE$o4X
4Rn i7qH
} }NXESZYoi
V("1\
_biJch
/* D/WS
**SiteInfoBean.java {JgN^R<5<f
*/ OOCeZ3yF(
package NetFox; kWd'gftQ
t/Fe"T[,V
UU;:x"4
public class SiteInfoBean { z#4g,)ZX
7'S]
66*o2D\Q*G
private String sSiteURL; //Site's URL PwW@I~@>
private String sFilePath; //Saved File's Path 'gGB-=yvbO
private String sFileName; //Saved File's Name bv/b<N@4?$
private int nSplitter; //Count of Splited Downloading File wO#+8js
KB= z{g
]YP?bP,:
public SiteInfoBean() n1Jz49[r
{//nSplitter的缺省值为5 U6Ak"
//default value of nSplitter is 5 ThxrhQ q[+
this("","","",5); l+6(|"md
} (=j!P*
4B`Rz1QBy
MQ44uHJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5qy}~dQ
{ 3o>t~Sfi
sSiteURL= sURL; eW0=m:6
sFilePath = sPath; /Hmo!"W`
sFileName = sName; T8-$[ 2
this.nSplitter = nSpiltter; Qx;A; n!lw
.KN]a"]
e`r;`a&
} y~7lug
#A;Z4jK
16|S 0 )
public String getSSiteURL() WFP\;(YV
{ h86={@Le
return sSiteURL; YHYB.H)
} {O)&5
W#j,{&KVn
SK52.xXJ
public void setSSiteURL(String value) 4Z}{hc\J
{ s?k[_|)!
sSiteURL = value; "44?n <1
} &J$5+"/;X
Wi^rnr'Ss
I?>T"nV +'
public String getSFilePath() )\vHIXnfJ1
{ {R;M`EU>
return sFilePath; yU,xcq~l
} p'~5[JR:
x[UO1% _o-
u9w&q^0dqG
public void setSFilePath(String value) <R>z;2c
{ 070IBAk}_
sFilePath = value; )1Nnn
} RFY!o<
-G#k/Rz6
sG2 3[t8
public String getSFileName() E]U0CwFtr
{ `Xdxg\|
return sFileName; KVxb"|[
} /T)n5X
acQNpT
4iqmi<[("
public void setSFileName(String value) Z4ioXl
{ k&iDJt
sFileName = value; MdZgS#`
} dM{~Ubb
DA`sm
#G` ,
public int getNSplitter() aLt{X)?
{ }Xj_Y]T
return nSplitter; d~-p;i
} ROS"VV<
g ypq`F
7CM03R[P
public void setNSplitter(int nCount) h6y4Ii
{ f\|?_k]
nSplitter = nCount; {@__%=`CCS
} K#hYbDm
} qO{ ZZ*
2,V+?'^j
PMhhPw]
/* ir:~*|
**Utility.java P 4*MV
*/ wI@I(r~g
package NetFox; ]^jdO##M
u#WTh%/
917 0bmr
public class Utility { S?\hbM]V-o
Y{vwOs
QM_X2Ho
public Utility() r/hyW6e_
{ cO+Xzd;838
V<ApHb
fGf-fh;s
} ikN!ut
8<g#$(a_E
//线程睡眠 $?J+dB
public static void sleep(int nSecond) igBrmaY'
{ o 7W Kh=
try{ 5b1uD>,;y
Thread.sleep(nSecond); ITIj=!F*
} `1bX.7K43
catch(Exception e) bro
{ h^+C)6(58n
e.printStackTrace (); k\sM;bCv7
} Nv?-*&L
} |"YA<e %
/CI%XocB
//日志 ?koxt44
public static void log(String sMsg) 0T#xM(q[K
{ N&^xq_9&
System.err.println(sMsg); h@;)dLo0z
} 'K`Rbhy
~,*YmB=Z
T<+ht8&M8
public static void log(int sMsg) I+"?,Ej$K
{ $.Q>M]xH
System.err.println(sMsg); R G0S
} p&sK\
} VkDS&g~Ws
(y~laW!
MATgJ`lsy
/* mvq7G
**TestMethod.java PB(
*/ mPfUJ#rS
package NetFox; 1%spzkE 3P
o9Txo (tYU
qwF*(pTHq
public class TestMethod { S2&9#6
%8bzs?QI
+an^e'
public TestMethod() 3p3WDL7
{ ///xx/weblogic60b2_win.exe {[,Wn:
try{ zn V1kqGU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )nNCB=YF!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'ZC}9=_g
SiteFileFetch fileFetch = new SiteFileFetch(bean); B3dA%\'
fileFetch.start(); [.j]V-61
} #PslrA. E
catch(Exception e){e.printStackTrace ();} w3=)S\
FL`1yD^2
Xqg.kX
} (D>y6r>r
XpgV09.EE
| 7 m5P@X
public static void main(String[] args) dv'E:R(a
{ =@JS88+
new TestMethod(); n</k/Mk}
} qcTmsMpj
} c.(Ud`jc
点击下载更多相关资料