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)); XKttZOiGT
} i;jw\ed
for(int i=0;i<nEndPos.length-1;i++) u7[ykyV
{ QP)pgAc
nEndPos = nStartPos[i+1]; %Nhx;{
} ,TPISs
nEndPos[nEndPos.length-1] = nFileLength; AW_(T\P:u
} c^u"I'#Q
} /X(t1+
#qI= Z0Y
{u\Mj
//启动子线程 e7(ucE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TUDr\' @/f
for(int i=0;i<nStartPos.length;i++) ? glSC$b
{ IOoz^/'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j!4et;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a1.Ptf eW|
nStartPos,nEndPos,i); _$f9]bab
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]*FVz$>XM
fileSplitterFetch.start(); vj\dA2!~
} *R3f{/DK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PBxCx3a{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X4t s)>"d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;A'Z4=*~
nEndPos = " + nFileLength); 2 :mn</z
// fileSplitterFetch[nPos.length-1].start(); I8<,U!$
!+4cqO
079'(%
//等待子线程结束 H(2]7dRS%
//int count = 0; xw T%),
//是否结束while循环 M57T2]8,
boolean breakWhile = false; w{uuSe
T2Y,U {
gO,25::")
while(!bStop) xY U.D+RY
{ 2fS[J'-o
write_nPos(); eDJfU
Utility.sleep(500); ~aOuG5XK
breakWhile = true; '+vA\(K
IlE_@gS8
UkHY[M7;
for(int i=0;i<nStartPos.length;i++) rEv*)W
{ t|<NI+H(e
if(!fileSplitterFetch.bDownOver) ~J8pnTY
{ i|}[A
breakWhile = false; psC mbN
break; !]fQ+*X0g
} q7Dw_<
} o{EC&-
if(breakWhile) iMFgmM|
break; OY5OJ*
Wg0g/
Ns0cgCrhX
//count++; vRxM4O~"
//if(count>4) (_*5oj-
// siteStop(); X*Dj[TD]
} W4U@%b do
lGk{LO)
pY~,(s|Qb
System.err.println("文件下载结束！"); b0A1hb[|
} qY$qaM^=
catch(Exception e){e.printStackTrace ();} *B\H-lp?
} Vc%R$E%
qc!MG_{Y
v-Fg +
//获得文件长度 ;w-qHha
public long getFileSize() {W~q z^>u4
{ pM&YXb?
int nFileLength = -1; V8wKAj Ux
try{ B Ma)O
URL url = new URL(siteInfoBean.getSSiteURL()); @81Vc<dJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~+bGN
httpConnection.setRequestProperty("User-Agent","NetFox"); +:-57
^1x*lLf
npyAJp
int responseCode=httpConnection.getResponseCode(); M- 2Tz[
if(responseCode>=400) ls`,EFF
{ +|{RE.DL
processErrorCode(responseCode); #E+gXan
return -2; //-2 represent access is error o|iYd n\
} c8M2 ^{O,`
aJe^Tp(
^eGNgE
String sHeader; CWG6;NT6m
wHv]ViNvXE
3bd5FsI^pU
for(int i=1;;i++) \U?n+6 7g
{ 1s*.A6EP"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); je4w=]JV
//Utility.log(in.readLine()); tpEI(9>
sHeader=httpConnection.getHeaderFieldKey(i); 5P+t^\
if(sHeader!=null) :@xm-.D
{ IU]^&e9u
if(sHeader.equals("Content-Length")) TtDg*kZ
{ 1w0OKaF5
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )wtaKF.-
break; ~i_Tw#}
} Q2];RS3.
} X$\i{p9jw
else fiI $T:g.
break; 5P hX"7
} <U9/InN0[
} EQIo5
catch(IOException e){e.printStackTrace ();} {"H2 :-t<
catch(Exception e){e.printStackTrace ();} %F9{EXJy
o}'bv
\cJ-Dd
Utility.log(nFileLength); ]PP:oriWl
W Qzj[
lhYn5d)DV
return nFileLength; ";w}3+R
} #W2[
|nk3^;Yf
l\!-2 T6Y
//保存下载信息（文件指针位置） ]G}B 0u3
private void write_nPos() Q2%QLM:.,
{ O:/yAc`
try{ 0l#)fJo
output = new DataOutputStream(new FileOutputStream(tmpFile)); qxJQPz
output.writeInt(nStartPos.length); 9H]Lpi^OH
for(int i=0;i<nStartPos.length;i++) =}fd6ea(o
{ h2;z4
// output.writeLong(nPos); Dli^2hD
output.writeLong(fileSplitterFetch.nStartPos); Ld,5iBiO:
output.writeLong(fileSplitterFetch.nEndPos); Hv<'dt$|
} 5;TuVU.8Q
output.close(); x2#qg>`l
} XfzVcap
catch(IOException e){e.printStackTrace ();} PaCzr5!~f
catch(Exception e){e.printStackTrace ();} jSQ9.%4
} >(tn"2
B)h>8 {
X0+fsf<H}
//读取保存的下载信息（文件指针位置） ]Lqt(c
private void read_nPos() p'?w2YN/
{ xaKst p
try{ 8?Y['
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i~{ _eQV
int nCount = input.readInt(); ,Ci/xnI
nStartPos = new long[nCount]; yISD/ g
nEndPos = new long[nCount]; w*w?S
for(int i=0;i<nStartPos.length;i++) L1)@z8]
{ tue/4Q#7
nStartPos = input.readLong(); =vh8T\
nEndPos = input.readLong(); %YlTF\-
} MYnH2w]
input.close(); @gBE{)Fj
} "x&C5l}n
catch(IOException e){e.printStackTrace ();} z&3]%t `C
catch(Exception e){e.printStackTrace ();} >1irSUj"~
} A~{f/%8D
AzpV4(:an.
snp v z1iS
private void processErrorCode(int nErrorCode) d2ENm%q*PX
{ )06iV
System.err.println("Error Code : " + nErrorCode); "n\%_'R\hH
} E)t
8C.!V =@\
6j8<Q 2
//停止文件下载 jUjr6b"
public void siteStop() !m{2WW-
{ 9-bG<`v\E
bStop = true; H.O(*Q=
for(int i=0;i<nStartPos.length;i++) , Ut Hc]
fileSplitterFetch.splitterStop(); [ij,RE7,T
g>7Y~_}
22KI]$D#f
} jV7&Y.$zF]
} >n7["7HHk
//负责部分文件的抓取 YirC*
**FileSplitterFetch.java eE/%6g
*/ {rkn q_;0
package NetFox; WA.\*Nqze
kJ: 2;t=
]Bb7(JX
import java.io.*; mKg@W;0ML
import java.net.*; 02]xJo
JFqf;3R
"gNK><
public class FileSplitterFetch extends Thread { /'>;JF
!Zwf 397
]~a_d)
String sURL; //File URL Inuc(_I
long nStartPos; //File Snippet Start Position ?Nl"sVCo
long nEndPos; //File Snippet End Position >e8JK*Blz
int nThreadID; //Thread's ID bv\ A,+
boolean bDownOver = false; //Downing is over Zy wK/D
boolean bStop = false; //Stop identical ~%q7Vmk9
FileAccessI fileAccessI = null; //File Access interface |r~ uos
iM64,wnA
.:;fAJPf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %7`d/dgR
{ Wm6dQQ;Bj
this.sURL = sURL; )hL^+Nn bR
this.nStartPos = nStart; !J.rM5K
this.nEndPos = nEnd; d0C8*ifFO
nThreadID = id; '=TTa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9Nl*4
} U %:c],Fk
S[@6Lp3q_
9|K*G~J
public void run() ':;LrTc'K
{ Ww87
while(nStartPos < nEndPos && !bStop) q?VVYZXP
{ ":&|[9/
&9kiO
rqvU8T7A
try{ 6dT|;koWbm
URL url = new URL(sURL); 2_olT_#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :2q ?>\
httpConnection.setRequestProperty("User-Agent","NetFox"); p\txlT
String sProperty = "bytes="+nStartPos+"-"; AZ8UXq
httpConnection.setRequestProperty("RANGE",sProperty); pa] TeH
Utility.log(sProperty); -v*x V;[
\FI^Vk
^~I @ spR4
InputStream input = httpConnection.getInputStream(); X"J%R/f
//logResponseHead(httpConnection); iE{Oit^aG
`03<0L
+IsWI;lp
byte[] b = new byte[1024]; >1XL;)IL>
int nRead; dx359
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x9*ys;~w
{ g@(30{
nStartPos += fileAccessI.write(b,0,nRead); CB@B.)E
//if(nThreadID == 1) |,fh)vO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); By/bVZks
} Pt3[|4L
`Wwh`]#"~d
3GWrn,f
Utility.log("Thread " + nThreadID + " is over!"); u@"o[e':
bDownOver = true; ty;o&w$
//nPos = fileAccessI.write (b,0,nRead); aT/KT,!
} ,(hY%M&\
catch(Exception e){e.printStackTrace ();} KS>Fl->
} pFH?/D/q
} L9'-
cd"wNH-
2TCRS#z
//打印回应的头信息 &(\@sxAyZ
public void logResponseHead(HttpURLConnection con) }@4|7
{ y84XoDQ
for(int i=1;;i++) 2vXGO|W
{ uk{J@&F
String header=con.getHeaderFieldKey(i); G+Ei#:W,
if(header!=null) rH^/8|}&s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o(SuUGW
Utility.log(header+" : "+con.getHeaderField(header)); 6Wu*.53
else InX{V|CW?
break; o;'4c
} fsb=8>}63}
} Pu/lpHm|
=[8d@d\
QW:Z[?39^
public void splitterStop() 0JOju$Bl,
{ [b pwg&Oo
bStop = true; 0kz7 >v
} f8F1~q
"x.88,T6
?ZM^%]/+
} Kk56/(_S
kBUufV~
;op'V6iG
/* _PdAN= C3
**FileAccess.java 1uj05aZh}
*//文件访问(定位，写) c; d"XiA
package NetFox; $u-lo|
import java.io.*; up7x)w:
QZ9M{Y/
a#6,#Q"
public class FileAccessI implements Serializable{ ;C6O3@Q
IM2/(N.%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t"#lnG!G
RandomAccessFile oSavedFile; Fj48quW1\P
long nPos; FRD<0o/`
*@=fq|6l 2
aliQ6_
public FileAccessI() throws IOException \c'%4Ao
{ 0I6499FQ
this("",0); xP{m9_Qj
} KXDz'9_
JiUT\y
dnLo(<{<U
public FileAccessI(String sName,long nPos) throws IOException DD)mN) &T
{ IFkvv1S`
oSavedFile = new RandomAccessFile(sName,"rw"); ?RqTbT@~
this.nPos = nPos; aq$62>[
oSavedFile.seek(nPos); u<J2p?`\&`
} U &f#V=Rg
CJtr0M<U+
\_)02ZT:
public synchronized int write(byte[] b,int nStart,int nLen) tgS+"ugl
{ _;%.1H{N
int n = -1; R\i]O
try{ ENpaaW@!Y
oSavedFile.write(b,nStart,nLen); 4E,hcu
n = nLen; re2Fv:4{
} eF*TLI<[^I
catch(IOException e) qLu8!|QT
{ }b<87#Nb9R
e.printStackTrace (); ArLz;#AOn
} yg.\^C
u>j5`OXo
DPR;$yV
return n; z;``g"dSw
} [Ja(ArO3|[
,$ho2R),Fn
W'm!f
} !e9N3Ga
]Sk#a-^~
{: Am9B
/* #xD&z^o
**SiteInfoBean.java Jq=X!mTd.
*/ -DbH6u3
package NetFox; GC,vQ\
?T$*5d
:H~UyrN
public class SiteInfoBean { 5n-9#J$
gizmJ:<
&T5fH!?4
private String sSiteURL; //Site's URL []sB^UT
private String sFilePath; //Saved File's Path s,{RP0|
private String sFileName; //Saved File's Name Y8{T.\%\+
private int nSplitter; //Count of Splited Downloading File >}xAg7\^
w50.gr7
OYQXi
public SiteInfoBean() u)N2
{//nSplitter的缺省值为5 ;Hz`0V
//default value of nSplitter is 5 |SwZi'p
this("","","",5); ..v@Q%
} 1D3dYVE
.eZPp~[lAN
d"QM;9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2D\x-!l/
{ 'Y~8_+J?
sSiteURL= sURL; a 5~G
sFilePath = sPath; /gMa"5?,
sFileName = sName; OtrXYiKB
this.nSplitter = nSpiltter; @+QYWh'
9y d-&yDG
<Hq6]\<
} G "c&C
VPq5xSc?
{66Q" H"I
public String getSSiteURL() @1`W<WP
{ *FI5z[8,
return sSiteURL; /ynKKJx<Y
} N{0+C?{_
)VV4HoH]8
:G6 xJlE|
public void setSSiteURL(String value) ~_/<PIm
{ \Nh^Ig
sSiteURL = value; D]LFX/hlH
} 5yO#N2jY\
3> n2
pGZl.OI
public String getSFilePath() |e.3FjTH
{ XSL t;zL:
return sFilePath; mfp`Iy"}+
} ~{3o(gzl
n9mM5H47
ImT+8pa
public void setSFilePath(String value) %nG~u,_2f
{ tDuUAI54
sFilePath = value; CBz(hCaI
} f6dE\
cN[q)ts
CguU+8]
public String getSFileName() zO7lsx2=
{ Rd;~'gbG
return sFileName; %Hl:nT2M
} 3=G5(0
y~#R:&d"
Hz;jJ&S
public void setSFileName(String value) &zg$H,@Qp
{ v3VLvh2)n
sFileName = value; \M3NasZ
} b>>=d)R
v"Ud mv"
D KMbs
public int getNSplitter() ,~ia$vI}R
{ "\R@lUx.Y
return nSplitter; ]w&?k:y>
} tSh}0N)
fs)q7 7g
G74a9li@
public void setNSplitter(int nCount) ]'bQ(<^#
{ cr=FMfhB
nSplitter = nCount; O. .@<.
} ~[ ks|
} Cs~\FI1wR
`hQ!*f6
}GU6Q|s[u[
/* sQ3ayB`
**Utility.java S:B-nI
*/ "*H'bzK
package NetFox; a_}BTkfHa
T/spUlWu
D/%b@Ls2ze
public class Utility { IZ(CRKCGBl
07G*M ]
>sl1 cC
public Utility() QVZ6;/
{ [(.T%kJ
Zia|`}peW
U}C#:Xi>$
} zdpLAr
0o^#Fmuz
//线程睡眠 WriJco<v
public static void sleep(int nSecond) >TJKH^7n
{ ^VLUZ
try{ |Bf:pG!
Thread.sleep(nSecond); Q1>Op$>h
} 1SJHX1CxX
catch(Exception e) =LeVJGF
{ Wp~4[f`,
e.printStackTrace (); #I{Yf(2Z
} tRrY)eElS
} w _6Y+
1{fwr1b
//日志 Xta>
public static void log(String sMsg) eMPQ| W
{ FoelOq6
System.err.println(sMsg); \]e w@C
} !kk %;XSZ
gm%bxr@X~
3lrZ-k+S{
public static void log(int sMsg) >|o9ggL`J5
{ & b^*N5<Z
System.err.println(sMsg); B,na
} x2IU PM
} JI#Enh!Lv
=D"63fP1
)V =K#MCK
/* m^u&g&^
**TestMethod.java kjKpzdbD
*/ JgjL$n;F
package NetFox; dmMr8-w
#*aGzF
tH|Q4C
public class TestMethod { \oZUG
QT&Ws+@ s{
ah$7 Oudj
public TestMethod() 1#X=&N
{ ///xx/weblogic60b2_win.exe vgbjvyfN
try{ UFY~D"%/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZK_@.O+]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Dqcu$V]
SiteFileFetch fileFetch = new SiteFileFetch(bean); e.Q K%
fileFetch.start(); zxmI/]3+/
} JX,#W!d
catch(Exception e){e.printStackTrace ();} 1AkHig,
2P>za\
'L+BkE6+%
} 9h0,L/;\
R{y{
IqJ=\
public static void main(String[] args) $izpH
{ H?bsK~
new TestMethod(); [^BUhm3a
} N~<}\0
} la{:RlW
点击下载更多相关资料