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;fpQ_KL
} .%Ta]!0
for(int i=0;i<nEndPos.length-1;i++) X~<("
{ *EZHJt9
nEndPos = nStartPos[i+1]; U9A~9"O
} ZOQTINf
nEndPos[nEndPos.length-1] = nFileLength; /s[l-1zW
} *i- _6s
} f/Hm{<BY
0;:.B j
cnFI &,FM
//启动子线程 /`6ZAom9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "gne_Ye.
for(int i=0;i<nStartPos.length;i++) qLT>Mz)$%
{ 3`ELKq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `^FGwx@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bV$)!]V
nStartPos,nEndPos,i); YH%'t= <m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D[mSmpjE6&
fileSplitterFetch.start(); OVko+X`
} tdSfi<y5I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ar:*oiU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !2'jrJGc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L?Qg#YSd~
nEndPos = " + nFileLength); ( |PAx(
// fileSplitterFetch[nPos.length-1].start(); \CXQo4P
3`B6w$z>(
n;$5Cq!v=
//等待子线程结束 QzzW x2
//int count = 0; "9^j.
//是否结束while循环 "E8zh|m o
boolean breakWhile = false; J]G?Rc
1!1beR]
&b?LP]
while(!bStop) ALNc'MW!
{ -Gw$#!
write_nPos(); 1QU:?_\6@t
Utility.sleep(500); <X7FMNr[
breakWhile = true; Jnna$6G)B
L\&<sy"H
Sk:ws&D1u
for(int i=0;i<nStartPos.length;i++) t0nI('LX,
{ T:IW%?M
if(!fileSplitterFetch.bDownOver) e=Z, Jg
{ Sz^5b!
breakWhile = false; ;zIP,PMM
break; spGB)k,^
} oA =4=`
} qd#sY.|1
if(breakWhile) p"FW&Q=PN
break; C#t'Y*
sm\f0P!rv
|pmZ.r
//count++; LwK+:4$
//if(count>4) (q4),y<:[
// siteStop(); t@R ?Rgu3
} -GqT7`:(H4
ltgc:&=|@
n%k!vJ)]
System.err.println("文件下载结束！"); %c [F;ug
} BwBm[jtP
catch(Exception e){e.printStackTrace ();} YQpSlCCo 3
} h~p>re
Yb/i{@AJ
mdq;R*`
//获得文件长度 qnoNT%xazo
public long getFileSize() {.De4]ANh
{ CMCO}#
int nFileLength = -1; z%e8K(
try{ ~5 *5
URL url = new URL(siteInfoBean.getSSiteURL()); 3q'&j,,^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rc/nFl6#
httpConnection.setRequestProperty("User-Agent","NetFox"); 8:#rA*Y
Pp|*J^U 4
}yJ$SR]t
int responseCode=httpConnection.getResponseCode(); -,+q#F
if(responseCode>=400) CWNx4)ZGw
{ 8S<@"v
processErrorCode(responseCode); B?)@u|0
return -2; //-2 represent access is error @E-\ J7 yh
} m^#rB`0;L
d ,Y#H0`
&CIVL#];e
String sHeader; un=2}@ '
+q)5dYRzV
n#:N;T;\a
for(int i=1;;i++) K\$J4~EtG
{ :{ur{m5bX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8Y_ol#\L
//Utility.log(in.readLine()); 3Te^
sHeader=httpConnection.getHeaderFieldKey(i); 9:!gI|C
if(sHeader!=null) Z-U-N
{ ]miy/V }5
if(sHeader.equals("Content-Length")) 2OwV^-OG
{ TU GNq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hBFP1u/E'
break; |<Gl91
} ]ZoD'-,
} `d[1`P1i[
else *0}3t<5
break; ^kgBa27
} ~{D[ >j][
} 8?i7U<CB
catch(IOException e){e.printStackTrace ();} (&P9+Tl
catch(Exception e){e.printStackTrace ();} vi|R(&
kdCP
v9D22,K-
Utility.log(nFileLength); \T\b NbPn
2{Chu85
m1IKVa7-\}
return nFileLength; 6sE{{,OGB
} !p[9{U->o;
2PeR
-YjA+XP
//保存下载信息（文件指针位置） \/SQ,*O
private void write_nPos() H{AMZyV0/d
{ E!Zx#XP1
try{ 0z[dlHi
output = new DataOutputStream(new FileOutputStream(tmpFile)); d)[;e()
output.writeInt(nStartPos.length); TeWMp6u,r
for(int i=0;i<nStartPos.length;i++) `D":Q=:
{ |8.(XsN
// output.writeLong(nPos); $F/EJ>
output.writeLong(fileSplitterFetch.nStartPos); [tH-D$V
output.writeLong(fileSplitterFetch.nEndPos); Sje wuIi1
} 7;tJK^J`
output.close(); !bD@aVf?5
} >rP#ukr5
catch(IOException e){e.printStackTrace ();} X!j{o
catch(Exception e){e.printStackTrace ();} T /mI[*1xI
} \(PohwWWo
_kdL'x
!{82D[5
//读取保存的下载信息（文件指针位置） +dPL>R
private void read_nPos() {\z({Wlb]
{ &%2*Wu;
try{ "&/]@)TPz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8:o<ry
int nCount = input.readInt(); ,j?.4{rHJ
nStartPos = new long[nCount]; SR8qt z/V
nEndPos = new long[nCount]; #k$)i[aI-
for(int i=0;i<nStartPos.length;i++) 4:sjH.u<
{ x%<
nStartPos = input.readLong(); ;),BW g
nEndPos = input.readLong(); (Si=m;g
} M@(^AK{mU
input.close(); KYkS9_yF
} i`0v#P
catch(IOException e){e.printStackTrace ();} =rd|0K"(r
catch(Exception e){e.printStackTrace ();} Jj=;
} O Lc}_
Ka|eFprS
jS!`2li?{
private void processErrorCode(int nErrorCode) `' 153M]
{ s3 ;DG
System.err.println("Error Code : " + nErrorCode); e*
} om3`[r[{
}%-t+Tf,
9Q!bt
//停止文件下载 @O}7XRJ_8
public void siteStop() $fpq 3
{ ~aXqU#8
bStop = true; Fa epDjY8
for(int i=0;i<nStartPos.length;i++) TS"D]Txs
fileSplitterFetch.splitterStop(); EQe5JFR
E"|4Y(G
$2MAZGJV
} aZk&`Jpz
} Dw2Q 'E
//负责部分文件的抓取 npDIX
**FileSplitterFetch.java zD)pF1,7:8
*/ DOQc"+
package NetFox; !>(RK"KWq]
OI0B:()
@+Y8*Rj\3
import java.io.*; =9G;PVk|
import java.net.*; oW$s xS
}Z`(aDH
T}D<Sc
public class FileSplitterFetch extends Thread { t0#[#I1+
8seBT;S
f{lZKfrp
String sURL; //File URL 6] z}#"
long nStartPos; //File Snippet Start Position )B!d,HKt;
long nEndPos; //File Snippet End Position A K/z6XGy
int nThreadID; //Thread's ID 70B)|<$
boolean bDownOver = false; //Downing is over k]rLjcB
boolean bStop = false; //Stop identical kLS(w??T
FileAccessI fileAccessI = null; //File Access interface tehUD&
)2Hff.
nd{R 9B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;$BdP7i:
{ DXQi-+?
this.sURL = sURL; %gcc y|
this.nStartPos = nStart; S*"u/b;
this.nEndPos = nEnd; -Z^4L
nThreadID = id; CkRX>)=py
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zQH]s?v
} _ jAo:K_Z
=C f(B<u
Dz_eB"}
public void run() DP7C?}(
{ 3P <'F2o
while(nStartPos < nEndPos && !bStop) [B0K
{ [rreFSy#@
h7;bclU
]$M<]w,IJ2
try{ cUK\x2
URL url = new URL(sURL); bO<0qM~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S^cH}-+
httpConnection.setRequestProperty("User-Agent","NetFox"); }wSy
String sProperty = "bytes="+nStartPos+"-"; HhkN^S,
httpConnection.setRequestProperty("RANGE",sProperty); uu%?K@Qq
Utility.log(sProperty); #^&jW
WjM>kWv
\h3e-)
InputStream input = httpConnection.getInputStream(); z]Acs
//logResponseHead(httpConnection); VG*'"y*%w
=!ac7i\F
f]d!hz!
byte[] b = new byte[1024]; Jbp5'e _
int nRead; E=/[s]@5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y~F<9;$=
{ ^GYq#q9Q
nStartPos += fileAccessI.write(b,0,nRead); TK>{qxt:=
//if(nThreadID == 1) 1]\TI7/n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b0a}ME&1
} L8V3BH7B
?Ay3u^X
(Q-I8Y8l8
Utility.log("Thread " + nThreadID + " is over!"); qi+&|80T.
bDownOver = true; Cj&$%sO1
//nPos = fileAccessI.write (b,0,nRead); r(}nhUQ%E
} K@@9:T$
catch(Exception e){e.printStackTrace ();} >Wh3MG6
} y67uH4&Vm
} kd;'}x=5yP
?An,-N-ezf
c6b0*!D"}
//打印回应的头信息 ZM~`Gd9K0E
public void logResponseHead(HttpURLConnection con) el'j&I
{ 98*x 'Wp
for(int i=1;;i++) %{STz
{ C=VIT*=
String header=con.getHeaderFieldKey(i); 00M`%c/
if(header!=null) p\U*;'hv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DMkhbo&+
Utility.log(header+" : "+con.getHeaderField(header)); D{AFL.r{
else 4YJ=q% G
break; jNy?[ )
} /#yA%0=w
} DzPs!(5[I
A/Khk2-:
wO"GtVd
public void splitterStop() i<u9:W
{ y3yvZD
bStop = true; jX|=n.#q
} Q#WE|,a
Sl.o,W^
Ko}2%4on
} :pd&dg!5
Bp0bY9xLg_
<lOaor c
/* (^H5EeGV{
**FileAccess.java )!C7bTv 4
*//文件访问(定位，写) <*YO~S(R
package NetFox; w4{y"A
import java.io.*; k,X74D+
aqfL0Rg+`
Zu=kT}aGg
public class FileAccessI implements Serializable{ } gkP
b%nkIPA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9bEM#Hj
RandomAccessFile oSavedFile; wZv-b*4
long nPos; n+quSF)
,#aS/+;[)
6+8mV8{-8
public FileAccessI() throws IOException \/,g VT
{ BPWnck=%
this("",0); l^,qO3ES
} aRKv+{K
k ]bPI$
? : md
public FileAccessI(String sName,long nPos) throws IOException @xJCn}`Zj
{ ] SK[C" S
oSavedFile = new RandomAccessFile(sName,"rw"); 6F`\YSn+
this.nPos = nPos; %FlA":W
oSavedFile.seek(nPos); 4zzlazU
} E0`[G]*G
MW]8;`|jC
Xb+3Xn0}&8
public synchronized int write(byte[] b,int nStart,int nLen) (zmNa}-
{ {{E jMBg{
int n = -1; cDO:'-
try{ C|$L6n>DR6
oSavedFile.write(b,nStart,nLen); /:Y9sz uW`
n = nLen; F;a3
} l7Y8b`
catch(IOException e) i>"dBJh]b
{ v?%3~XoH
e.printStackTrace (); .M+v?Ad
} &Y=.D:z<
3`rIV*&_{
eKJ:?Lxv;
return n; N<"`ShCNM
} %|jzEBz@
/=trj5h
1uC;$Aj6:
} ^5>du~d
"<*nZ~nE)
8;8YA1@w
/* {,F/KL^u
**SiteInfoBean.java +',^((o
*/ ?C~X@sq
package NetFox; <c\]Ct
NGj"ByVjx
[Gf{f\O
public class SiteInfoBean { d|3o/@k
+l.|kkZ?
`#=fA
private String sSiteURL; //Site's URL v D&Kae<
private String sFilePath; //Saved File's Path lJ'trYaq7
private String sFileName; //Saved File's Name Ym:{Mm=ud
private int nSplitter; //Count of Splited Downloading File S"{GlRpd
\2Xx%SX
Y.9~Bo<<r
public SiteInfoBean() 08O7F
{//nSplitter的缺省值为5 3/l\ <{
//default value of nSplitter is 5 u6p5:oJj,
this("","","",5); ,,}sK
} ,wlbIl~
1wbTqc
($:y\,5(9I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nIR*_<ow
{ +h|K[=l\
sSiteURL= sURL; E\_W
sFilePath = sPath; v}&#f&q!
sFileName = sName; )ZN(2z
this.nSplitter = nSpiltter; 'jN/~I
+/w(K,
363cuRP
} CvP`2S\
O!yakU+
r/^tzH's
public String getSSiteURL() 0w'|d@*wV
{ }ymc5-
return sSiteURL; ;fj9n-
} rWqkdi1
%P(;8sS
Kc-Y
public void setSSiteURL(String value) Gxo# !
{ n+X1AOE[L
sSiteURL = value; :4{Qh
} v8>!Gft
o|0 '0P
VkWO}
public String getSFilePath() ]u;GNz}?
{ 90?,-6
return sFilePath; V8\$`NEP
} m:b^,2"g
T^N L:78
-!i;7[N
public void setSFilePath(String value) v&e-`.xR
{ %8a=mQl1^
sFilePath = value; j=FMYd8$y
} Mq76]I%
xkF$D:sP
jzMhJ
public String getSFileName() 7TnM4@*f
{ ([[)Ub$U
return sFileName; /z..5r^,ZZ
} .r7D)xNa@
Q6eN+i2 ;
y{YXf!AS
public void setSFileName(String value) }Z"28?
{ kSB3KR;~n
sFileName = value; "$]ls9-%n
} -J{Dxz
{3.*7gnY\L
|OOXh[y
public int getNSplitter() Td5bDO
{ ss/h[4h4h
return nSplitter; O<4Q$|=&?
} 2wGF-V
p "/(>8
tF<^9stM
public void setNSplitter(int nCount) #"hJpyW 4V
{ 7[4_+Q:}
nSplitter = nCount; ^GE^Q\&D&
} =d}gv6v2S
} *Yj~]E0`1
+:fqL
5r^1CFO
/* Qk+=znJ
**Utility.java W]Y@WKeT
*/ ]cn/(U`
package NetFox; ?]s%(R,B5
~5FS|[1L
txj wZ_p
public class Utility { @bc[ eas
Y||yzJdC
mfu*o0
public Utility() P4hZB_.=
{ fL(':W&n-
5ze`IY
I/mvQxp
} 0[V&8\S~'T
(m<R0
//线程睡眠 .=>\Qq%
public static void sleep(int nSecond) yJF 2
{ .Ln;m8
try{ `l+ >iM
Thread.sleep(nSecond); $dlnmNP+
} gsLr=
catch(Exception e) ov?.:M
{ I/^q+l.=`{
e.printStackTrace (); )w Z49>Y
} Y8D7<V~Md
} p.@0=)
uo]Hi^r.l
//日志 nu;}S!J
public static void log(String sMsg) 30A`\+^f
{ QpdujtH`
System.err.println(sMsg); bc `UA
} K?5B>dv@A
J ZVr&KZN
6.7`0v?,n
public static void log(int sMsg) .tZjdNE(h
{ 8W19#?7>B
System.err.println(sMsg); Gojl0?
} \?bwm&6+r
} 1 ;_{US5FR
aEcktg6h
bHhC56[M
/* OT-n\sL$
**TestMethod.java Zk~nB}Xw
*/ cEDDO&u
package NetFox; "WF( 6z#
S 23S.]r
) 1lJ<g#
public class TestMethod { aDm-X r
1$:{{%
gGtep*k
public TestMethod() w o-O_uZB
{ ///xx/weblogic60b2_win.exe v+xgxQGYH
try{ :)KTZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -D!#W%y8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IUh5r(d 68
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1$='`@8I
fileFetch.start(); qT4I Y$h
} opUKrB
catch(Exception e){e.printStackTrace ();} .nj?;).
c[wQJc
#,f}lV,&
} *kX3sG$8
|@o]X?^
JLy)}8I
public static void main(String[] args) w5dIk]T
{ d8Q_6(Ar|
new TestMethod(); XBfiaj
} ,W)IVc
} q|47;bK'
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