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)); f2*e&+LjTP
} wqx9
for(int i=0;i<nEndPos.length-1;i++) qcVmt1"
{ zDD
nEndPos = nStartPos[i+1]; ~<Eu @8+_
} +f){x9 :
nEndPos[nEndPos.length-1] = nFileLength; g \;,NW^
} JE~;gz]
} 1n3XB+*
}Od=WQv+
zWO!z=
//启动子线程 Z;'5A2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T<ka4
for(int i=0;i<nStartPos.length;i++) ]H {g/C{j
{ ^55q~DP}>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lZ'ZL*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >~}}*yp
nStartPos,nEndPos,i); Pt=@U:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /#Gm`BT
fileSplitterFetch.start(); O\X=vh/D
} ^1w<wB\B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }q?*13iy(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FlyRcj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]39])ul
nEndPos = " + nFileLength); Z,_EhEm
// fileSplitterFetch[nPos.length-1].start(); nN'>>'@>
APUpqY
cgV5{|P
//等待子线程结束 $?*XPzZ
//int count = 0; =WEWs4V5A
//是否结束while循环 v;.w*x8Jw
boolean breakWhile = false; wl Nl|+ K
4(mRLr%l@`
jJ7"9
while(!bStop) f\u5=!kjN
{ |Duf 3u
write_nPos(); SO+J5,)HA
Utility.sleep(500); #,S0uA
breakWhile = true; W<\*5oB%H
}$oZZKS
GhC%32F
for(int i=0;i<nStartPos.length;i++) Z}`A'#!
{ m?y'Y`
if(!fileSplitterFetch.bDownOver) K<vb4!9Z9
{ g0M/Sv
breakWhile = false; K)P].htw
break; .2f0e[J
} zwgO|Qg;
} >>.4@
if(breakWhile) 1$v1:6
break; OV`#/QL
w)<h$<tU
4<A+Tf
//count++; Y;1J`oT
//if(count>4) BDcA_=^R&
// siteStop(); 5 8n(fdE
} OE(!^"5?[
@u1mC\G
bnxR)b~
System.err.println("文件下载结束！"); 9$=o({
} E>&oe&`o'
catch(Exception e){e.printStackTrace ();} m%.7l8vT
} NGAjajB
NaC}KI`
tW \q;_DSr
//获得文件长度 ,K8(D<{
public long getFileSize() $@eFSA5k,7
{ BE,H`G #h
int nFileLength = -1; 5@`DS-7h
try{ !3Ed0h]Bfa
URL url = new URL(siteInfoBean.getSSiteURL()); 4^{~MgQWK+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *:,y`!F=y
httpConnection.setRequestProperty("User-Agent","NetFox"); (k<__W c_t
vx4Jk]h+=L
f1RX`rXf
int responseCode=httpConnection.getResponseCode(); :eL ja*
if(responseCode>=400) B+n(K+
{ 822jZ sb
processErrorCode(responseCode); l^4!
return -2; //-2 represent access is error "dFuQB
} 5u^;71
gB}UzEj^<
PJ'.s
String sHeader; MzCZj
>@i{8AD
M|\C@,F]8
for(int i=1;;i++) "Rq)%o$Z
{ %z5P%F'5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZfSAXr "(
//Utility.log(in.readLine()); 2R`/Oox
sHeader=httpConnection.getHeaderFieldKey(i); +I_p\/J?w/
if(sHeader!=null) F'3-*>]P
{ [LrA_N
if(sHeader.equals("Content-Length")) <"}WpT
{ 4kdQ h]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {, zg
break; +i6XCN1=
} h$I 2T
} 2[TssJQ
else jLgx(bMn
break; vGI?X#w3
} "M4gl
} EP}NT)z,{
catch(IOException e){e.printStackTrace ();} &Ez]pKjB
catch(Exception e){e.printStackTrace ();} -40OS=wpA
X)k+BJ
@Yy']!Ju
Utility.log(nFileLength); N cnL-k.
O*y@4AR"S
d}_%xkC
return nFileLength; F]7$Y
} nN[gAM (
pi?[jU[Tn
1)N{!w`
//保存下载信息（文件指针位置） XbL\l
private void write_nPos() +Rb0:r>kU
{ HE>sZ;
try{ $H2HVJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); q'4qSu
output.writeInt(nStartPos.length); _M9-n
for(int i=0;i<nStartPos.length;i++) M}*#{UV2
{ h!UB#-
// output.writeLong(nPos); @N,I}_9-
output.writeLong(fileSplitterFetch.nStartPos); "8YXFg
output.writeLong(fileSplitterFetch.nEndPos); CxW-lU3G`
} |m /XGr
output.close(); Vs~!\<?
} ^lCQHz
catch(IOException e){e.printStackTrace ();} )Y:9sd8g7
catch(Exception e){e.printStackTrace ();} T{Rhn V1
} "f-z3kL
~76qFZe-
E]26a,^L
//读取保存的下载信息（文件指针位置） .P>-Fh,_p
private void read_nPos() =(U&?1R4
{ +Xjevg6DU
try{ \"^.>+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g4fe(.?c,
int nCount = input.readInt(); bcCCvV}6WZ
nStartPos = new long[nCount]; aO]FQ#l2b
nEndPos = new long[nCount]; A/+bwCDP
for(int i=0;i<nStartPos.length;i++) 8>y!=+9_
{ %.+#e
nStartPos = input.readLong(); -F+dmI,1$
nEndPos = input.readLong(); ON~K(O2g(
} gkN )`/`*
input.close(); F4%vEn\!
} m:A1wL4c6
catch(IOException e){e.printStackTrace ();} qq1@v0
catch(Exception e){e.printStackTrace ();} n'-?CMH`
} d:V6.7>,
|KQkmc
j/<z[qr
private void processErrorCode(int nErrorCode) ]E/~PV
{ DD]e0 pa
System.err.println("Error Code : " + nErrorCode); WFBVAD
} mtQlm5l
|#6))Dh
]sf1+3
//停止文件下载 Z<,$XvL
public void siteStop() '3MCb
{ (T]<
bStop = true; &+Iv"9
for(int i=0;i<nStartPos.length;i++) 6YCFSvA#/
fileSplitterFetch.splitterStop(); `43X? yQ
a7Fc"s*
n,E=eNc
} NLLLt
} n)'5h &#
//负责部分文件的抓取 #~Z55D_
**FileSplitterFetch.java c>(`X@KL
*/ v>&sb3I
package NetFox; :~1sF_
'l| e}eti>
/QeJ#EHn
import java.io.*; 7Ib/Cm0d|
import java.net.*; X/D^?BKC
\~#$$Q-qtU
}>|M6.n "
public class FileSplitterFetch extends Thread { U(jZf{`Mz
?pAO?5Z:}
.%'$3=/oe
String sURL; //File URL =QiVcw,G#
long nStartPos; //File Snippet Start Position w>q:&Q
long nEndPos; //File Snippet End Position ^^-uq)A
int nThreadID; //Thread's ID }zkMo?
boolean bDownOver = false; //Downing is over P})Iwk|Z
boolean bStop = false; //Stop identical n4YedjHSN
FileAccessI fileAccessI = null; //File Access interface F{g^4
F;Lg w^1!
)TmqE<[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [9:'v@Ph
{ YR{%pZp
this.sURL = sURL; 9EE},D
this.nStartPos = nStart; ![{>$Q?5
this.nEndPos = nEnd; `a!:-.:v
nThreadID = id; k[6xuyY]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z DP
} xgX"5Czvv`
4K(AXk
`Z}7G@ol
public void run() n8!qz:z/
{ ;-OnCLr
while(nStartPos < nEndPos && !bStop) huu v`$~y
{ \GR M,c
|9;6Cp
} +@H&}u
try{ &@c?5Ie5
URL url = new URL(sURL); D?v)Xqw=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $E_9AaX
httpConnection.setRequestProperty("User-Agent","NetFox"); QEavbh^S
String sProperty = "bytes="+nStartPos+"-"; _ 2WG6y;
httpConnection.setRequestProperty("RANGE",sProperty); m5G9 B-\?
Utility.log(sProperty); :< )"G&
v[aFSXGj)
b&y"[1`
InputStream input = httpConnection.getInputStream(); x}`]9XQ
//logResponseHead(httpConnection); u]B15mT?
0u?{"xH{+}
\uumNpB*n
byte[] b = new byte[1024]; #q06K2
int nRead; <*g!R!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,Tb~+z|-[
{ 5,>Of~YN
nStartPos += fileAccessI.write(b,0,nRead); Y=%SK8]Q;
//if(nThreadID == 1) nTJ-1A7EP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N(%%bHi#V
} \WDL?(G<
|NbF3 fD
m#D+Yh/y{n
Utility.log("Thread " + nThreadID + " is over!"); $#cZJ@;]
bDownOver = true; Nn"[GB
//nPos = fileAccessI.write (b,0,nRead); b.`<T"y
} +@'{
catch(Exception e){e.printStackTrace ();} Vr1Wr%
} ,ZpcvK/S
} UN~dzA~V
`m~x*)L#
x}g5
//打印回应的头信息 LDj'L~H
public void logResponseHead(HttpURLConnection con) {*=+g>RgD
{ AhZ`hj
for(int i=1;;i++) U{IY F{;@
{ %uuh+@/&yz
String header=con.getHeaderFieldKey(i); -+'fn$
if(header!=null) j|`6[93MG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3'd(=hJ45$
Utility.log(header+" : "+con.getHeaderField(header)); #Ub"Ii
else qk;vn}auD]
break; m15MA.R>
} I9! eL4e
} 0ssKZ9Lc
1]yOC)u"i
iqzl(9o.D
public void splitterStop() (,5oqU9s@
{ |ZEZ@y^
bStop = true; b`NXe7A
} Yy 4EM
+GgJFBl
0_}^IiG
} Lx{bR=
6sRe. ct<
y$n7'W6
/* Sv*@3x
**FileAccess.java )Ir_:lk
*//文件访问(定位，写) zW`Zmt\T2
package NetFox; AML8.wJ
import java.io.*; +N161vo7
jpL'y1@Ut
"6T: &>
public class FileAccessI implements Serializable{ N30w^W&
"[`.I*WNo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _%HpB=
RandomAccessFile oSavedFile; Qfhhceb6#J
long nPos; Xx;RH9YYz
lpW|GFG
z*Y4t?+
public FileAccessI() throws IOException b.qp&2A
{ `w_?9^7mH
this("",0); F1V[8I.0
} ~~U2Sr
tEz6B}
Km~\^(a '
public FileAccessI(String sName,long nPos) throws IOException /PP\L](
{ V:M$-6jv
oSavedFile = new RandomAccessFile(sName,"rw"); O"otzla
this.nPos = nPos; ^y@RfM=A
oSavedFile.seek(nPos); F^5<o
} ZE#f{qF(
btq`[gAF\
GCxtWFXH
public synchronized int write(byte[] b,int nStart,int nLen) ]J^9iDTTA
{ {HV$hU+_)Q
int n = -1; < bHu9D
try{ \]y4e^FZZ
oSavedFile.write(b,nStart,nLen); p_!;N^y.
n = nLen; a:C'N4K
} ;().
catch(IOException e) 5xZ*U
{ 7wt2|$Qz
e.printStackTrace (); Wsn}Y-x
} S~"1q 0
NO4V{}?a
1Aq*|JSk(
return n; v1hrRf2<
} By=/DVm)=
lVywc:X
=e7,d$i
} `{g8A P3
(fgX!G[W
&"dT/5}6
/* tuA,t
**SiteInfoBean.java gf]biE"k
*/ ;!<WL@C~
package NetFox; xCH,d:n=
r`]&{0}23
bl|k6{A
public class SiteInfoBean { $or?7 w>
7s%DM6li 6
W11Wv&
private String sSiteURL; //Site's URL fP`g#t)4Tu
private String sFilePath; //Saved File's Path 7@g8nv(p
private String sFileName; //Saved File's Name GS|sx
private int nSplitter; //Count of Splited Downloading File q#W|*kL3
IVYWda0m
73/kyu-0%
public SiteInfoBean() %H:uE*WZ
{//nSplitter的缺省值为5 z`-?5-a]I
//default value of nSplitter is 5 }$W4aG*[
this("","","",5); SWr?>dl
} so|5HR|
1xM'5C?~7
`fEB,0j^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &sL(|>N
{ yp=Hxf
sSiteURL= sURL; QRnkj]b
sFilePath = sPath; CW k#Amt.
sFileName = sName; >=hOjV;
this.nSplitter = nSpiltter; 3kFOs$3
@psyO]D=j%
*loPwV8
} 6#XB'PR2p
bkkhx,Oi[G
PF@+~FI
public String getSSiteURL() H4LZNko
{ W=M`Bkw{
return sSiteURL; xwa5dtcng
} A87JPX#R?
Ktg{-Xl
2Yt#%bj7^
public void setSSiteURL(String value) 5uMh#dm^
{ u2 a U0k:
sSiteURL = value; 2"lDKjj
} {S(d5o8
2g1[E_?
jC1mui|Y^
public String getSFilePath() {hB7F"S
{ tS,nO:+x
return sFilePath; )W)m?%
} zVe@`gc
FX7=81**4
!b0'd'xe
public void setSFilePath(String value) MZf$8R
{ }^WQNdws56
sFilePath = value; yiGq?WA7
} 5Jq~EB{"
jq#_*&Eg]
$$~x: iN
public String getSFileName() :G9+-z{Y&
{ uZ( I|N$
return sFileName; Etty{r}
} ^RytBwzKM
?-0k3
g1VdP[Y#
public void setSFileName(String value) }$3eRu +
{ Yu-e|:
sFileName = value; IW3ZHmrpA
} Xn-GSW3{
9@ [R>C
r(iT&uz
public int getNSplitter() QlJ cj+_h
{ L^} Z:I
return nSplitter; G$pTTT6#
} Y~Y-L<`I
y0cHs|8
$9<q'hf<w
public void setNSplitter(int nCount) ;vvO#3DWM
{ /PG+ s6
nSplitter = nCount; F,Q\_H##x4
} <l]P <N8^
} tGnBx)J|
Wr Ht
0UZ>y/ C)=
/* )orVI5ti
**Utility.java XL@i/5C[
*/ n4Nb,)M
package NetFox; R>SS\YC'X
>c%OnA,3
G'IqAKJ
public class Utility { _O)xE9t#ru
Bz<T{f
nmZz`P9g
public Utility() "V-k_d "
{ hc OT+L>
V(_OyxeC{2
vdw5T&Q{{C
} IWcgh`8
P'.MwS
//线程睡眠 pSp/Qpb-B
public static void sleep(int nSecond) "s!!\/^9C
{ |N_tVE
try{ bA}9He1
Thread.sleep(nSecond); $U%M]_
} ^Pl(V@
catch(Exception e) [ZC]O2'
{ /ivcqVu]
e.printStackTrace (); 2Ya)I k{
} it]im
} FsQeyh>
0/K?'&$yvb
//日志 hhd%j6
public static void log(String sMsg) MB.\G.bV
{ S:)Aj6>6
System.err.println(sMsg); >qj.!npQD
} U-Ia$b-5!
uQh dg4
< kyT{[e+6
public static void log(int sMsg) 9A_{*E(wd
{ &*2\1;1tB
System.err.println(sMsg); 0K/Pth"*
} p}q27<O*/
} I5]=\k($
R_9&V!fl
e_'/4 n
/* iV9wqUkMv
**TestMethod.java yg({g "
*/ =k.:XblEe[
package NetFox; DV+M;rs
"XPBNv\>_
tUX4#{)q(j
public class TestMethod { 0XouHU
m2c>RCq
kc*zP=
public TestMethod() @z $,KUH
{ ///xx/weblogic60b2_win.exe =&+]>g{T
try{ N>h/!# ZC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cr GFU?8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x_za R}WI
SiteFileFetch fileFetch = new SiteFileFetch(bean); kk|7{83O
fileFetch.start(); OAigq6[,
} y?=W
catch(Exception e){e.printStackTrace ();} VnlgX\$}
5mzOr4*0
J%VcvBaJm
} /|7@rH([{
b"D? @dGB,
_#[~?g`
public static void main(String[] args) 7# >;iGuz
{ Mc8|4/<Z
new TestMethod(); 8CXZ7p
} lT.Q)(
} &d,chb(
点击下载更多相关资料