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)); aX:#'eDB
} 5DmCxg
for(int i=0;i<nEndPos.length-1;i++) #"|"cYi,
{ S!u6dz^[$X
nEndPos = nStartPos[i+1]; dD:
} T4Xtuu1
nEndPos[nEndPos.length-1] = nFileLength; 4,gol?a
} =rtS#u Y
} yi sF5`+
xGwTk
poTl|y @
//启动子线程 bkxk i@t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?rky6
for(int i=0;i<nStartPos.length;i++) ]Jja
{ IkiQOk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !T)T_P[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ng?apaIi@~
nStartPos,nEndPos,i); u,:CJ[3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j l}!T[5
fileSplitterFetch.start(); Fecx';_1`
} Cc@=?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]d[Rf$>vu0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~*jsB=XM/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @gH(/pFX
nEndPos = " + nFileLength); @X3 gBGY)
// fileSplitterFetch[nPos.length-1].start(); 2f`WDL
@][ a8:Y9I
w/?nUp
//等待子线程结束 lv=yz\
//int count = 0; e 4 p*51ra
//是否结束while循环 q-A`/9
boolean breakWhile = false; fEx+gQW_
hN Z4v/
vsu@PuqH
while(!bStop) x%_qJ]o
{ oNiToFbQu
write_nPos(); ^fFtI?.6jI
Utility.sleep(500); R)sp
breakWhile = true; 3Ne9%"
i7i|370
#;wkr))
for(int i=0;i<nStartPos.length;i++) Uzan7A
{ /'R UA
if(!fileSplitterFetch.bDownOver) DZ%g^DRZX
{ nYI/&B{p
breakWhile = false; b`(yu.{Jn
break; 9`)w@-~~
} +9F^F>mu
} NFrNm'v
if(breakWhile) A2}Z *U(;
break; |h#DL$
JZs|~@
,k4z;
//count++; >2]Eaw&W
//if(count>4) *i=?0M4S
// siteStop(); w{_e"N
} +A]&AkTw
Y&oP>n! ei
):/<H
System.err.println("文件下载结束！"); y_}K?
} ~C}(\8g
catch(Exception e){e.printStackTrace ();} ?2JS&i
} 3g?MEM~
${jA+L<J
Kj~>&WU
//获得文件长度 XR{5]lKt_
public long getFileSize() v< 65(I>
{ NmH}"ndv+
int nFileLength = -1; 2E@C0HaL
try{ A6@+gP<
URL url = new URL(siteInfoBean.getSSiteURL()); C ffTv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UgF)J
httpConnection.setRequestProperty("User-Agent","NetFox"); gi1}5DR
o|rGy5
O\|C,Epm
int responseCode=httpConnection.getResponseCode(); XV74Fl
if(responseCode>=400) s[0prm5.
{ s|{^ }4{
processErrorCode(responseCode); I}*]m%'-Y
return -2; //-2 represent access is error Ma`
} aHBByH
}V1DyLg:
K$Mx}m7l
String sHeader; 3EbnZb
[(D}%+2
NZfo`iHAN
for(int i=1;;i++) a}5vY
{ O0K@M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H]%mP|
//Utility.log(in.readLine()); ?c|`R1D
sHeader=httpConnection.getHeaderFieldKey(i); U6/m_`nc
if(sHeader!=null) :0J-ek.;
{ "'Q"(S
if(sHeader.equals("Content-Length")) kr/1Dsr4
{ {u(}ED#p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x?k
break; A^T~@AO
} SX_kr^#
} "sX[p
else +t7c&td\
break; n.Ur-ot
} %0ll4"
} eZ8Y"i\!y
catch(IOException e){e.printStackTrace ();} *@\?}cX
catch(Exception e){e.printStackTrace ();} XPc9z}/(e
*tq|x[<
o*O"\/pmF
Utility.log(nFileLength); OH-~
~>Hnf_pZO
C }h<ldlY
return nFileLength; #`N6<nb
} q5?rp|7D
bWX[<rh'
4%',scn
//保存下载信息（文件指针位置） ~xlMHf
private void write_nPos() +LQs.*
{ :=iM$_tp'
try{ !T#8N7J>
output = new DataOutputStream(new FileOutputStream(tmpFile)); /ygUd8@
output.writeInt(nStartPos.length); >,] eL
for(int i=0;i<nStartPos.length;i++) =0@d|LeZ
{ eB(S+p?
// output.writeLong(nPos); @w#gRQCl
output.writeLong(fileSplitterFetch.nStartPos); ijZydn
output.writeLong(fileSplitterFetch.nEndPos); =u:6b} =
} ]AFM Y<mB
output.close(); u>3&.t@hU1
} 6g~o3
catch(IOException e){e.printStackTrace ();} i-i}`oN
catch(Exception e){e.printStackTrace ();} MrKU,-
} |mQtjo
)"pxry4v7J
ery?G-
//读取保存的下载信息（文件指针位置） ZZ]OR;8
private void read_nPos() @MlU!oR&
{ <WHs
try{ "a0u-}/D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~kSnXJv
int nCount = input.readInt(); V(''p{
nStartPos = new long[nCount]; ig.6[5a\
nEndPos = new long[nCount]; .^)C:XiW
for(int i=0;i<nStartPos.length;i++) +AgkPMy
{ !"Oj$c -
nStartPos = input.readLong(); ^?K?\
nEndPos = input.readLong(); 2d>d(^
} :YRzI(4J
input.close(); U!;aM*67
} "dLMBY~
catch(IOException e){e.printStackTrace ();} lkSz7dr@
catch(Exception e){e.printStackTrace ();} (8@hF#N1
} :ET3&J L
MoKXl?B<
|;Se$AdT#
private void processErrorCode(int nErrorCode) )]>i>
{ o$HJg
System.err.println("Error Code : " + nErrorCode); XTi0,e]5{u
} (4{@oM#H6
?,i#B'Z^
sS1J.R
//停止文件下载 o7@4=m}
public void siteStop() V'.eesN
{ bWC~Hv
bStop = true; yqVaA 'w5
for(int i=0;i<nStartPos.length;i++) *OGXu07 !
fileSplitterFetch.splitterStop(); Gwrx)Mq
+,F= -
ax{-Qi7z-+
} lU50.7<08
} }^GV(]K
//负责部分文件的抓取 }eDX8b8emA
**FileSplitterFetch.java QqFfR#
*/ c&Su d, &
package NetFox; Nz>E#.++
wsb=[$C
;qVEI/
import java.io.*; sw qky5_K
import java.net.*; E/L?D
m)[wZP*e
h@>rjeY@
public class FileSplitterFetch extends Thread { G5QgnxwP2
/nMqEHCyg
'/yx_RK2?
String sURL; //File URL $Op/5j
long nStartPos; //File Snippet Start Position {^$"/hj
long nEndPos; //File Snippet End Position VQ,\O
int nThreadID; //Thread's ID WEV{C(u<k!
boolean bDownOver = false; //Downing is over K}5$;W#
boolean bStop = false; //Stop identical vu.S>2Wv
FileAccessI fileAccessI = null; //File Access interface s!o<Pd yJK
X$9D0;L
E~Up\f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aIt 0;D
{ Am=PUQF$
this.sURL = sURL; P#2TM
this.nStartPos = nStart; $OFFH[_z
this.nEndPos = nEnd; XUqE5[O%
nThreadID = id; jXDzjt94J
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Uhx2 _
} RJ@e5A6_
|_xiG~
"w|k\1D
public void run() IrwF B
{ seD+~Y\z
while(nStartPos < nEndPos && !bStop) xX4^nem\G
{ 'xrbg]b%
*}iT6OJ
Wn,g!rB^@
try{ |C2.Zay
URL url = new URL(sURL); CIik@O*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;,B@84'
httpConnection.setRequestProperty("User-Agent","NetFox"); E?q'|f
String sProperty = "bytes="+nStartPos+"-"; 1'U%7#;E
httpConnection.setRequestProperty("RANGE",sProperty); -ZoOX"N}
Utility.log(sProperty); vVN[bD<
"6NNId|Y
M"$RtS|h
InputStream input = httpConnection.getInputStream(); ]MA)='~
//logResponseHead(httpConnection); bQN4ozSi
by y1MgQd
sImxa`kb
byte[] b = new byte[1024]; J0WXH/:
int nRead; K?OX
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zn 5m.=z
{ /h.3<HI."*
nStartPos += fileAccessI.write(b,0,nRead); eNC5' Z
//if(nThreadID == 1) Jp*AIj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VU'l~%ql
} JK8@J9(#
(PrPH/$
<ZvPtW
Utility.log("Thread " + nThreadID + " is over!"); BLH3$*,H
bDownOver = true; ,l?76g
//nPos = fileAccessI.write (b,0,nRead); fUWm7>6VA>
} 0?L$)T-B
catch(Exception e){e.printStackTrace ();} Xiedgy
} w>q_8V_K
} ]aW.b_7<9
[MXXY
?QIQ,?.
//打印回应的头信息 <sFf'W_3{
public void logResponseHead(HttpURLConnection con) B l/e>@M
{ z` ?xS
for(int i=1;;i++) 2u;fT{(
{ YIk6:W{
String header=con.getHeaderFieldKey(i); |v'5*n9
if(header!=null) 5sCky)N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b!HFv;^N
Utility.log(header+" : "+con.getHeaderField(header)); ;WAu]C|
else _ktSTzH0
break; ?d#(ian
} ?'#;Y"RT
} (X7yNIPfA
MGC0^voe
-bu. *=
public void splitterStop() [3NV #
{ ~t3?er& R
bStop = true; ,H(vD,54g
} n2hsG.4
k'q !MZU
9C~GL,uKs
} n *0F
dZYJ(7%
^Jpd9KK
/* U"kK]Stk<
**FileAccess.java td$6:)
*//文件访问(定位，写) xENA:j?kF
package NetFox; 44{:UhJkx
import java.io.*; 3K:Xxkk
&ziB#(&:H
h?tV>x/Fu
public class FileAccessI implements Serializable{ W",jZ"7
>Ez}r(QQ^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 daJ-H
RandomAccessFile oSavedFile; so&3A&4cL
long nPos; (qONeLf%
os ud
i1&noRGl
public FileAccessI() throws IOException I}0-
{ I,?LZ_pK
this("",0); ][qA@3^Tw
} 4qR Q,g{$T
&|FG#.2yw
tl^;iE!-
public FileAccessI(String sName,long nPos) throws IOException c+XR
{ W]7?;#Hpk
oSavedFile = new RandomAccessFile(sName,"rw"); FsZEB/c
this.nPos = nPos; sh3}0u+
oSavedFile.seek(nPos); Ec/+9H6g
} BU\NBvX$
cJ{P,K
xx#Ef@bS
public synchronized int write(byte[] b,int nStart,int nLen) 9.}3RAB(cv
{ r~a}B.pj
int n = -1; [/^g) ^s:
try{ m,_oX1h
oSavedFile.write(b,nStart,nLen); 1fp&"K:yR
n = nLen; a'fb0fz
} SygsZv&LZ
catch(IOException e) g+{MvSj$
{ ?UIb!k>
e.printStackTrace (); NPq2C8:
} ~i {)J
TU6EE
~a)20
return n; r|$g((g
} "d*
dQo$^?
`u)V9{
} 1fG@r%4
KA[Su0
~z"->.u
/* x6P^IkL:
**SiteInfoBean.java 2!`Z3>Oa
*/ A[Xw|9
package NetFox; !LESRh?
~$Yuxo
p`C5jfI
public class SiteInfoBean { 05DtU!3O
~_6rD`2cJ
y!Eh /KD
private String sSiteURL; //Site's URL bJvRQrj*3
private String sFilePath; //Saved File's Path cZi&L p
private String sFileName; //Saved File's Name artS*fv3r
private int nSplitter; //Count of Splited Downloading File N4FG_N
<m\TZQBD
v2SsfhT
public SiteInfoBean() S+ x[1#r
{//nSplitter的缺省值为5 U_04QwhK7
//default value of nSplitter is 5 A]slssE+
this("","","",5); N* QI>kzU
} {GY$J<5=
RAa1KOxZX
-#hl&^u$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d@~)Wlje
{ #-8/|_*
sSiteURL= sURL; zoXF"Nz
sFilePath = sPath; #wcoLCjs)
sFileName = sName; {K}+$jzGVt
this.nSplitter = nSpiltter; #]a0 51Y
q\G@Nn^
-rrg?4
} gNBI?xs`p
EyiM`)!5
34:=A0z
public String getSSiteURL() DtX{0p<T3
{ !o7.L%S
return sSiteURL; Iu]P^8
} )oCF| 2qc
U^S0H(>
n+w>Qz'
public void setSSiteURL(String value) @B <_h+
{ WbF\=;$=7
sSiteURL = value; Ro69woU
} -A~<IyPt
MsiSC
n%hnL$!z
public String getSFilePath() vOU-bF%u
{ ekXHfA!i%
return sFilePath; :2+:(^l
} owB)+
pQJZE7S
W@LR!EW)
public void setSFilePath(String value) \wP$"Z}j
{ B;$5*3D+
sFilePath = value; ny0`~bl{p
} eAEVpC2
UbXz`i
xC]/i(+bA
public String getSFileName() aeIR}'H|
{ x3 <Lx^;
return sFileName; G#>nOB
} ME"/%59r
F ry5v?22
sP#5l @
public void setSFileName(String value) *HUqW}_r
{ B:SRHd{*Wu
sFileName = value; *&km5@*
} Sr0mA M
Smo'&x
tVwN92*J
public int getNSplitter() K,Vl.-4?
{ ?uLqB@!2
return nSplitter; v,! u{QP
} iW)Ou?aS
hi%>&i*
{WChD&v
public void setNSplitter(int nCount) 9hQ{r 2
{ -vQ`}e1
nSplitter = nCount; m"5gzH
} +VDB\n
} y[# U/2
A.Njn(z?Lz
c s>W6
/* nN:i{t4f
**Utility.java GbhaibkO
*/ ^[6AOz+L
package NetFox; )Lq FZ~B
yWy9IWI["
}_S]!AWz
public class Utility { E^G=
BRT2=}A
(plOV)
public Utility() V3S`8VI
{ tBt\&{=|D
Gvwel!6
!|]%^G
} bZ=d!)%P-{
G9]GK+@&F
//线程睡眠 '?nhpT^
public static void sleep(int nSecond) ?:,j9:m?
{ "Y6f.rB
try{ V_:/#G]jeG
Thread.sleep(nSecond); &F)lvtt|
} *@< jJP4
catch(Exception e) =619+[fK
{ <?!#QA
e.printStackTrace (); Cs<d\"+
} JyV"jL
} (_D#gr{S=
|1EM )zh6
//日志 5_PD?lg
public static void log(String sMsg) KpWQ;3D2
{ g]S.u8K8m
System.err.println(sMsg); DY%E&Vd:h
} }Q*8QV
:%{8lanO
;G?_^ 0
public static void log(int sMsg) Z^b1i`v
{ R lv|DED$
System.err.println(sMsg); S;= D/)[mr
} D`+'#%%x
} 8"? t6Z;5
%*,'&S
eD(#zfP/+
/* #R &F
**TestMethod.java %',. K)IR
*/ $?7}4u,
package NetFox; \ FA7 +Q
*v6'I-#
z}Q54,9m
public class TestMethod { H}d&>!\}F
nI-\HAX
V`G]4}
public TestMethod() D(y=0),
{ ///xx/weblogic60b2_win.exe [/I4Pe1Yj%
try{ arnu|paw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3.Y/ZWON
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0HE@L_$;2
SiteFileFetch fileFetch = new SiteFileFetch(bean); =6ojkTk
fileFetch.start(); zg|]Ic
} 2$|WXYY
catch(Exception e){e.printStackTrace ();} `.@N9+Aj
<EJC.WWJa
/" ,]J
} R/iXO~/"J
jGId)f!)
&uC7W.|
public static void main(String[] args) 0q81H./3
{ A^G%8 )\
new TestMethod(); z.FO6y6L
} U:p<pTnMR
} a *>$6H;
点击下载更多相关资料