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)); }lhJt|qc
} /q8n_NR
for(int i=0;i<nEndPos.length-1;i++) \OOj]gAe
{ eI- ~ +.
nEndPos = nStartPos[i+1]; $L?stgU
} <#:"vnm$j
nEndPos[nEndPos.length-1] = nFileLength; Y1+f(Q
} WO]dWO6Mm
} __)9JF
<MY_{o8d
x}-rAr
//启动子线程 #[IQmU23
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zc(-dMlK
for(int i=0;i<nStartPos.length;i++) t0/fF'GZD
{ N~SG=\rP;o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "xw2@jGpG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z[|(}9v?~
nStartPos,nEndPos,i); N1_nBQF )
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^/c&Ud
fileSplitterFetch.start(); =8[HC}s|$
} 0LxA+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;gf^;%FK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w+PbT6;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]U]{5AA6
nEndPos = " + nFileLength); gg5`\}
// fileSplitterFetch[nPos.length-1].start(); i4AmNRs
Krz[ f
NFsMc0{
//等待子线程结束 <jfi"SJu
//int count = 0; 2Ui)'0
//是否结束while循环 {4UlJ,Z.n
boolean breakWhile = false; "#(]{MY
IS"UBJ6p
Yk[yG;W
while(!bStop) FD[*mCGZ
{ )'92{-A0
write_nPos(); pkhZW8O
Utility.sleep(500); Aqq%HgY:t
breakWhile = true; \S3C"P%w
/8lGP!z
8xlj:5;(w
for(int i=0;i<nStartPos.length;i++) 0/;T\9
{ +\SbrB P
if(!fileSplitterFetch.bDownOver) "h\{PoG
{ DqbN=[!X~n
breakWhile = false; [K,&s8N5
break; 6dV92:
} Bx2E9/S3
} Q']:k}y
if(breakWhile) e%#9|/uP
break; Bm1yBKjO
dX` _Y
g;Bq#/w
//count++; #NwlKZ-
//if(count>4) Sw>AgES
// siteStop(); zAS&L%^tV
} Gb\}e}TB[
^<7)w2ns
{6*h';~
System.err.println("文件下载结束！"); 's+ Fd~'
} TAIcp*)ZM
catch(Exception e){e.printStackTrace ();} IYb@@Jzo
} xqX~nV#TB
}>fL{};Z"
4, 8gf2
//获得文件长度 mbU[fHyV
public long getFileSize() &$|k<{j[<f
{ Cj,fP[p#7
int nFileLength = -1; ZI-)'
try{ JuKj
URL url = new URL(siteInfoBean.getSSiteURL()); 9-I;'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P*Uu)mG)G
httpConnection.setRequestProperty("User-Agent","NetFox"); |&o%c/
/$0@To
mq do@
int responseCode=httpConnection.getResponseCode(); tNoo3&
if(responseCode>=400) /EA4-#uw
{ =&< s*-l[
processErrorCode(responseCode); &CG3_s<2
return -2; //-2 represent access is error \@3i=!
} +kmPQdO;*/
x/R|i%u-s
l0 rZril
String sHeader; {eMu"<
>n{(2bcFs
9co1+y=i{
for(int i=1;;i++) k5P&F
{ Kw+?Lowp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); UXnd~DA
//Utility.log(in.readLine()); z{7&=$
sHeader=httpConnection.getHeaderFieldKey(i); Y6,< j|
if(sHeader!=null) p(:$HP)R
{ ;spuBA)[X
if(sHeader.equals("Content-Length")) 5a&[NN
{ 25o + ?Y<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &Dgho
break; Jr==AfxyT
} j"7 z
} L Lm{:T7
else ]+{Cy\*kR
break; bo4 :|Z
} ebcGdC/%>
} bBb$0HOF
catch(IOException e){e.printStackTrace ();} O sbY}*S
catch(Exception e){e.printStackTrace ();} 25NZIal<
]4@_KKP
1}}.e^Tsfr
Utility.log(nFileLength); D N GNc
GTyS8`5E*
j|A *rzL8
return nFileLength; mpIRe@#Z
} 5M;fh)fT
~6Vs>E4G
b`usRoD{+
//保存下载信息（文件指针位置） g>CF|Wj
private void write_nPos() C7[_#1Oz
{ TwqyQ49
try{ |)B&-~a+p
output = new DataOutputStream(new FileOutputStream(tmpFile)); @{:E&K1f
output.writeInt(nStartPos.length); *1$rg?yGf
for(int i=0;i<nStartPos.length;i++) ~ b!mKyrZ
{ Ola>] 0l
// output.writeLong(nPos); BOQ2;@:3
output.writeLong(fileSplitterFetch.nStartPos); W7c(] tg.
output.writeLong(fileSplitterFetch.nEndPos); hCD0Zel
} hHm&u^xY
output.close(); +^iUY%pm
} By]XD~gcP
catch(IOException e){e.printStackTrace ();} &jT>)MXPu
catch(Exception e){e.printStackTrace ();} U@@#f;&
} Nq/,41
NIY0f@1z-
,2qJXMg"=$
//读取保存的下载信息（文件指针位置） |<96H8
private void read_nPos() U}x2,`PI
{ mVcpYyD|k
try{ 5wmH3g#0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S#8wnHq
int nCount = input.readInt(); YR@@:n'TP
nStartPos = new long[nCount]; 1Thr74M
nEndPos = new long[nCount]; #I'W[\l~+
for(int i=0;i<nStartPos.length;i++) q.yS j
{ <UQaRI[55
nStartPos = input.readLong(); $W<H[k&(B
nEndPos = input.readLong(); j7K9T
} 7[rn ,8@
input.close(); rRRiqmq
} 3k`"%R.H
catch(IOException e){e.printStackTrace ();} idMb}fw>
catch(Exception e){e.printStackTrace ();} 'ejuzE9
} @Y 1iEL%\y
R rs?I,NV
&^Zo}F2V
private void processErrorCode(int nErrorCode) D}XyT/8G3
{ b8P/9D7K?
System.err.println("Error Code : " + nErrorCode); v`A^6)U#M
} @s}I_@
OB)Vk
S7N3L."
//停止文件下载 ,%w_E[2
public void siteStop() @Ck6s
{ OkGg4X|9
bStop = true; 8 k9(iS
for(int i=0;i<nStartPos.length;i++) nyWA(%N1
fileSplitterFetch.splitterStop(); M=HW2xn
"^u
DmEmv/N=
} &W:Wv,3
} s-Q-1lKV,
//负责部分文件的抓取 tSV}BM,
**FileSplitterFetch.java 7h?PVobe
*/ TviC1 {2
package NetFox; @C62%fU{5
:WIbjI=
!MSz%QcO
import java.io.*; =24)`Lyb
import java.net.*; TOdH
A)Wp W M
"#z4
public class FileSplitterFetch extends Thread { -l+&Bkf
VI,z7 \
\[Op:^S
String sURL; //File URL i;;CU9`E2q
long nStartPos; //File Snippet Start Position gV1&b (h
long nEndPos; //File Snippet End Position 4-^|e
int nThreadID; //Thread's ID <?kr"[cQeP
boolean bDownOver = false; //Downing is over @a#qq`b;
boolean bStop = false; //Stop identical VQ5T$,&
FileAccessI fileAccessI = null; //File Access interface v|t_kNX;v*
9:4PJ%R9
`e .;P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O6LZ<}oUR
{ ;ob-'
this.sURL = sURL; [7q~rcf,Z
this.nStartPos = nStart; w~y+Pv@
this.nEndPos = nEnd; rVowHP
nThreadID = id; 4j|]=58
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x tg3~/H
} >gM|:FG
:P#
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public void run() $'btfo4H
{ }@=m[Zx#
while(nStartPos < nEndPos && !bStop) Un@B D}@\
{ 4SCb9|/Q
yS p]+
A^ $9[_
try{ $j0]+vT
URL url = new URL(sURL); QFU;\H/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ';us;xR#
httpConnection.setRequestProperty("User-Agent","NetFox"); I1^0RB{~
String sProperty = "bytes="+nStartPos+"-"; S1(. AI~
httpConnection.setRequestProperty("RANGE",sProperty); ${0+LhST
Utility.log(sProperty); k<wX??'
S9d+#6rn
gm~Ka%O|F
InputStream input = httpConnection.getInputStream(); NX&mEz
//logResponseHead(httpConnection); km,}7^?F0r
mV^+`GWvo
I$xfCu
byte[] b = new byte[1024]; G`!#k!&r
int nRead; a97A{7I&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u:&gp
{ Yf&x]<rkCp
nStartPos += fileAccessI.write(b,0,nRead); ,+<NP}Yg#G
//if(nThreadID == 1) pm$,B7Q`oO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KGdL1~
} ,pE{N&p9
Zm& X $U
,u7:l
Utility.log("Thread " + nThreadID + " is over!"); !q=ej^(S
bDownOver = true; |0:<Z(
//nPos = fileAccessI.write (b,0,nRead); jjL(=n<J<"
} u'M\m7
catch(Exception e){e.printStackTrace ();} |K| c
} s<Pk[7`*
} ]n1@!qa48
.9{Sr[P
[U@#whEO
//打印回应的头信息 r7o63]
public void logResponseHead(HttpURLConnection con) G/>upnA{w
{ 5VdF^.:u
for(int i=1;;i++) wG6>.`:
{ hd1(q33
String header=con.getHeaderFieldKey(i); iIji[>qz
if(header!=null) Tn,'*D@l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XBe!9/'k>
Utility.log(header+" : "+con.getHeaderField(header)); W}#eQ|oCV
else 1.U5gW/3L
break; $Q*h+)g<
} K.4t*-<`[
} JYA$_T
RhIRCN9
?ORG<11a
public void splitterStop() dPgN*Bdv
{ Jj4!O3\I
bStop = true; +#7e?B
} W- 5Z"m1I
O`1_eK~1<
pe$" nUy|
} \)'s6>58|
ts/rV#s~
FB-?{78~
/* jPU:&1(_ n
**FileAccess.java iV;X``S
*//文件访问(定位，写) u^T)4~(
package NetFox; &QFg=
import java.io.*; bzD <6Z
Y ]&D;w
Uu ~BErEC
public class FileAccessI implements Serializable{ SE/GT:}
Y5e6|b|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p'z fo!
RandomAccessFile oSavedFile; 0)n#$d>
long nPos; Tl"GOpH\]
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}@%A@A{R
public FileAccessI() throws IOException >5-z"f
{ G6wBZ?)k
this("",0); !j[Oyr|
} h}r64<Y2{
?4v&TB@
Jk=E"I6
public FileAccessI(String sName,long nPos) throws IOException HLm6BtE
{ ]FV,}EZ
oSavedFile = new RandomAccessFile(sName,"rw"); k)j,~JH
this.nPos = nPos; W@U<GF1
oSavedFile.seek(nPos); w:%3]2c
} V("@z<b|
gFlUMfKh
`Mx&,;x
public synchronized int write(byte[] b,int nStart,int nLen) at"-X?`d
{ e]F4w(*=
int n = -1; <nDuN*|
try{ @H[)U/.
oSavedFile.write(b,nStart,nLen); .`qw8e}y#'
n = nLen; x&>zD0\ :\
} Q${0(#Nu
catch(IOException e) sbn|D\p
{ \`3YE~7J/
e.printStackTrace (); "cSH[/
} V ':?rEN|
;LEO+,6
{]Tb
return n; B^Y AKbY
} 6t@kft>Nv
A'Q=DoE
I-oY@l`
} pIcvsd
HUUN*yikj
k$]-fQM
/* }4G/x;D
**SiteInfoBean.java W$&{jr-p
*/ #nG?}*#
package NetFox; a&oz<4oT
klSzmi4M
vzDoF0Ts*p
public class SiteInfoBean { S5B12P
#+$pE@u7A
n?uVq6c
private String sSiteURL; //Site's URL L[v-5u)
private String sFilePath; //Saved File's Path nO-1^HUl
private String sFileName; //Saved File's Name $&IF#uDf
private int nSplitter; //Count of Splited Downloading File ]6JI((
sXe=4`O
ig G8L
public SiteInfoBean() Y:UDte[Lb
{//nSplitter的缺省值为5 xZ2^lsY
//default value of nSplitter is 5 ~Q<h,P
this("","","",5); ?+6w8j%\
} `Hj{XIOx
=)tU]kp
Gp*U2LB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $TU)O^c
{ mx\b6w7
sSiteURL= sURL; jm~(OLg
sFilePath = sPath; dC&{zNG
sFileName = sName; -<e8\Z`
this.nSplitter = nSpiltter; TNgf96) y
X{2))t%
r(qAe{
} "p,TYjT?R
xnz(hz6
Wp5w}8g
public String getSSiteURL() +%Y`>1I^#
{ }<G"w5.<
return sSiteURL; "^?|=sQ
} +-8u09-F
gN"Abc
`2}H$D
public void setSSiteURL(String value) /m#!<t7
{ E<=h6Ha
sSiteURL = value; C8^=7HEB
} `{1`>5
(jQ]<q%P
tzl`|UwF
public String getSFilePath() #s"|8#
{ AH?T}t2
return sFilePath; NR98I7
} 5Z (1&
gie.K1@|
VE_%/Fs,
public void setSFilePath(String value) LHy-y%?i
{ X0G Mly
sFilePath = value; fK-tvP0}*
} "v%|&@
R 2.y=P8N
XLG6f(B=F
public String getSFileName() {~cG'S Y%
{ W=Y?_Oz
return sFileName; -s]
} JQ9JWu%a
"l83O8 L
2y_R05O0
public void setSFileName(String value) M{sn{
{ >$^v@jf
sFileName = value; =^nb-9.
} e G8Zn<:s
RDFOUqS
X9:4oMux7
public int getNSplitter() g7>p,
{ 8Xo`S<8VS
return nSplitter; 1w30Vj2<
} I@sXmC2$\
CqF=5z:A
]mED3#
public void setNSplitter(int nCount) t,CC~
{ <OYy;s
nSplitter = nCount; x{=@~c%eh
} hu=b,
} kTCWyc
Kr;7~`$[
G"_ 8`l
/* \W^+aNbv=8
**Utility.java :Fvd?[
*/ 7&I+mw/X
package NetFox; RU r0K#]
PP+-D~r`}
u0& aw
public class Utility { r$=YhI/=
J~\`8cds
fi/[(RBG
public Utility() Kzv*`
{ sg=mkkD!g
M@R_t(&=
x37pj)i/
} R78=im7
/Dh[lgF0C
//线程睡眠 n_8wYiBs(
public static void sleep(int nSecond) $ N7J:Q
{ rSGt`#E-s.
try{ GQU9UXe
Thread.sleep(nSecond); t&GjW6]W
} ch^tq",1>
catch(Exception e) ;,z[|"y
{ xr }jw
e.printStackTrace (); +N~?_5lv\s
} &HS6}
} 3n\eCdV-b<
vai.w-}Z
//日志 oH[4<K>
public static void log(String sMsg) ig] hY/uT
{ jjs1Vj1@<
System.err.println(sMsg); uude<d"U
} .H.#W1`
e~wuoE:M3
=*ZQGM3w
public static void log(int sMsg) aa:97w~s0
{ &7gL&AY8
System.err.println(sMsg); L `7~~
} ,g2oqq ?
} .:<-E%
!3E %u$-}
gEejLyOag
/* =z=$S]qN
**TestMethod.java `2 vv8cg^
*/ _A8x{[$
package NetFox; wUd6xR
EQ;,b4k?&g
>:2Br(S
public class TestMethod { z x7fRd$
~Sr`Tlp
ka3(sctZ5
public TestMethod() 3L;GfYr0
{ ///xx/weblogic60b2_win.exe ujo3"j[b
try{ 6NvdFss'A{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p4ML }q8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >o#5tNm
SiteFileFetch fileFetch = new SiteFileFetch(bean); iMrNp
fileFetch.start(); "zT#*>U
} (x.O]8GKP
catch(Exception e){e.printStackTrace ();} 71nI`.Z
/& qN yo
f*+eu@
} h{dR)#)GF<
hQm"K~SW=
(#4
public static void main(String[] args) ?1r>t"e5
{ q~3dbj
new TestMethod(); O<@S,/Q4
} U[!x 0M
} $@[`/Uh
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