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)); UZzNVIXA%
} ]i-P-9PA4
for(int i=0;i<nEndPos.length-1;i++) ^I]LoG:
{ 'e}uvbK
nEndPos = nStartPos[i+1]; =yl4zQmg$
} v1LKU
nEndPos[nEndPos.length-1] = nFileLength; `wNm%*g
} ).pO2lLF4
} /8f>':zUb
an3~'g?
h/,R{A2mO
//启动子线程 u@<Pu@?xm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :lUX5j3
for(int i=0;i<nStartPos.length;i++) nN>J*02(
{ %b=Y <v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `_|aeoK_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L ;6b+I
nStartPos,nEndPos,i); hS4.3]ei
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dZPW2yf
fileSplitterFetch.start(); x>}B#
} )VNM/o%Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lc]V\'e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z)}3**3'y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j7K5SS_]
nEndPos = " + nFileLength); \ jECSV|
// fileSplitterFetch[nPos.length-1].start(); ToV6lS"
BbFa=H.
Hal7 MP
//等待子线程结束 }K2 /&kZ
//int count = 0; !_qskDc-
//是否结束while循环 w#oGX
boolean breakWhile = false; :*^:T_U
.:rmA8U[
b3}Q#Y\G
while(!bStop) k!T|)\nc+
{ q(,cYu
write_nPos(); 9X(Sk%
Utility.sleep(500); vB^uxdt|m
breakWhile = true; ]fj-`==
^V[/(Lq
=4eUAeH {w
for(int i=0;i<nStartPos.length;i++) :4|M jn
{ +#4]o }6G
if(!fileSplitterFetch.bDownOver) 4CLsY n?
{ g+/0DO_F3
breakWhile = false; @<2d8ed
break; D}-o+6TI?
} %;7.9%
} z5'ZN+
if(breakWhile) k}GjD2m
break; Y,C=@t@_
Q $]YD pCM
y,Jh@n';|
//count++; {3LA%xO
//if(count>4) _pW_G1U
// siteStop(); Av o|v>
} E!zX)|Z<
yMb|I~k
e&0K;yU
System.err.println("文件下载结束！"); $xT1 1 ^
} D|l,08n"?
catch(Exception e){e.printStackTrace ();} r4u z} jl{
} X1oGp+&
n#4Gv|{XMD
I.1D*!tz
//获得文件长度 Y6A;AmM8
public long getFileSize() t0q_>T-kt
{ +c--&tBo
int nFileLength = -1; iwU[6A
try{ =Q-k'=6\
URL url = new URL(siteInfoBean.getSSiteURL()); );Z]SGd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2:Q(Gl`<l
httpConnection.setRequestProperty("User-Agent","NetFox"); ;\qXbL7
P>(P2~$Y"
*:g_'K"+
int responseCode=httpConnection.getResponseCode(); gyev5txn
if(responseCode>=400) Z, T#,
{ rFey4zzz
processErrorCode(responseCode); pLnB)z?
return -2; //-2 represent access is error h./P\eDc
} yoQ\lk
4/'N|c.
XV>@B $hu
String sHeader; 'Dath>Y=
}$&xTW_
6V1:qp/6
for(int i=1;;i++) G(/DtY]
{ %?9Ok
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z\TLsx
//Utility.log(in.readLine()); ^z~~VBv
sHeader=httpConnection.getHeaderFieldKey(i); /ylc*3e'4
if(sHeader!=null) 9[VxskEh
{ /1d<P! H
if(sHeader.equals("Content-Length")) "UG K8x
{ gzf-)J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e"k/d<
break; OX\$nQ\o
} W\8Ln>
} Z(e^iH
else $'{=R 45Z
break; jnJZ#=)
} :U'Cor H
} $shp(T,q
catch(IOException e){e.printStackTrace ();} X:EEPGE
catch(Exception e){e.printStackTrace ();} 7C7>y/uS
7O)" `
FOH@OY
Utility.log(nFileLength); \S ."?!U
booRrTS
.TpsJXF
return nFileLength; Xgat-cy'DA
} [&#/|zH'j:
=sgdkAYwP
<41ZZ0<EwY
//保存下载信息（文件指针位置） NmpnJu|8
private void write_nPos() [=uIb._Wv
{ eKG2*CV
try{ /Vww?9U;
output = new DataOutputStream(new FileOutputStream(tmpFile)); =:=/Gz1
output.writeInt(nStartPos.length); `s"d]/85VW
for(int i=0;i<nStartPos.length;i++) d ~`V7B2Y
{ g`0moXz
// output.writeLong(nPos); nlGHT
output.writeLong(fileSplitterFetch.nStartPos); 3^,QIG
output.writeLong(fileSplitterFetch.nEndPos); iPj~I
} ^YlI>_3s
output.close(); TQ]dW
} 3@<zg1.9-
catch(IOException e){e.printStackTrace ();} 0N;%2=2_E
catch(Exception e){e.printStackTrace ();} -SCM:j%h
} 86 .`T l;
r.yK,
Z>P*@S,6G
//读取保存的下载信息（文件指针位置） w0lT%CPx
private void read_nPos() Bp?
{ =qu(~]2(
try{ w7TJv4_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $B(kZ
int nCount = input.readInt(); 33Az$GXFsq
nStartPos = new long[nCount]; 2C=Q8ayvX
nEndPos = new long[nCount]; @'6"7g
for(int i=0;i<nStartPos.length;i++) /=:j9FF
{ C! 9}
nStartPos = input.readLong(); =9wy/c$
nEndPos = input.readLong(); r^fe4b
} %,P>%'0
input.close(); *ZrSiIPP
} !t#F/C
catch(IOException e){e.printStackTrace ();} xHA0gZf
catch(Exception e){e.printStackTrace ();} Fc6iQ
} L|j%S
3=mr "&]r:
8LzBh_J?
private void processErrorCode(int nErrorCode) u<xo/=Z
{ =r2]uW9
System.err.println("Error Code : " + nErrorCode); I/6)3su%
} N2C7[z+l`
i^msjA
ac{?+]8}
//停止文件下载 ?)D^~/ A
public void siteStop() b KtD"JG\
{ S\i@s_
bStop = true; T{v>-xBRy
for(int i=0;i<nStartPos.length;i++) w_tJ7pz8T
fileSplitterFetch.splitterStop(); (Z]HX@"{J
Kn`M4O
>l']H*&B<
} 80OtO#1y
} p'_%aVm7
//负责部分文件的抓取 +]Zva:$#`
**FileSplitterFetch.java (V:E2WR
*/ @(g_<@Jz
package NetFox; baV>N[F&
W/$Zvl
QS[L~97m2M
import java.io.*; PNs~[
import java.net.*; =FP0\cQ.
4GdX/6C.
58Xzup_"
public class FileSplitterFetch extends Thread { e'%v1-&sP
"qz3u`[o
(t+;O;
String sURL; //File URL ZBT1Y.qA
long nStartPos; //File Snippet Start Position 46@{5)Tq
long nEndPos; //File Snippet End Position 'k0[rDFc#3
int nThreadID; //Thread's ID Pz*_)N}j >
boolean bDownOver = false; //Downing is over m0n)dje
boolean bStop = false; //Stop identical r0;:t
FileAccessI fileAccessI = null; //File Access interface YyAJ m^o
"TyJP[/
u$#Wv2|mk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q[q?hQ/b
{ a' Ki;]q
this.sURL = sURL; }je,")#W
this.nStartPos = nStart; S-Y=-"
this.nEndPos = nEnd; f5AjJYq1
nThreadID = id; \wcam`f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {%lXYMyu
} W]M)Q}:Y
Mips.Bx
D"(L5jR8m@
public void run() -VxTx^)>
{ 4fk8*{Y
while(nStartPos < nEndPos && !bStop) y;wx?1)
{ ULrr=5&8
!* Ti}oIo&
g9D^)V
try{ '.Ed`?<p
URL url = new URL(sURL); NX`*%K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o1W:ox?kO
httpConnection.setRequestProperty("User-Agent","NetFox"); v\16RD
String sProperty = "bytes="+nStartPos+"-"; O/AaYA&
httpConnection.setRequestProperty("RANGE",sProperty); @AHm!9?o
Utility.log(sProperty); c0B|F
g8qgk:}
A1'hlAGF
InputStream input = httpConnection.getInputStream(); )'17r82a
//logResponseHead(httpConnection); <h%O?mkC
{;toI
4#x5MM
byte[] b = new byte[1024]; $3`>{3x$
int nRead; ;<yd^Xs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {~!q`Dr3?q
{ @1.QEyXG
nStartPos += fileAccessI.write(b,0,nRead); *f&EoUk}F
//if(nThreadID == 1) NI#X@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NH$r Z7$
} \^ghdU
Dd;Nz
(?_S6HE
Utility.log("Thread " + nThreadID + " is over!"); qmO6,T-|
bDownOver = true; w0w G-R ?
//nPos = fileAccessI.write (b,0,nRead); G'3qzBJ#
} FZ!`B]]le,
catch(Exception e){e.printStackTrace ();} H 0+dV3
} il|1a8M2~
} ~P~
M@ed>.
;};wq&b#
//打印回应的头信息 z<H~ItX,n
public void logResponseHead(HttpURLConnection con) HGm 3+,
{ 6qcO?U
for(int i=1;;i++) @-UL`+
{ .>Ljnk
String header=con.getHeaderFieldKey(i); DXz}YIEC
if(header!=null) H*#s }9=kZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fRg`UI4w}
Utility.log(header+" : "+con.getHeaderField(header)); I%- " |]$
else =FE|+!>PA
break; 4`JH&))}
} iw*Nq,(
} afYc\-"
/|xra8?H[
J7r|atSk
public void splitterStop() aW>6NDq(
{ bh^LIU
bStop = true; ,-7R(iMd
} =-_B:d;
m(pE5B(
EwOV;>@T?
} V(Ub!n:j
K|dso]b/
.e_cgad :
/* ^]{R.(#z
**FileAccess.java ByCnD
*//文件访问(定位，写) z5)s/;Sc
package NetFox; .'Y]R3\M+
import java.io.*; 31/Edd"]
s kg*
&|/| ''A)
public class FileAccessI implements Serializable{ 0GJn_@hr
[Q=dCX9%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'fW6 .0fXa
RandomAccessFile oSavedFile; FQ=@mjh
long nPos; zN [2YJ$
eImn+_ N3
0v9rv.Y"
public FileAccessI() throws IOException HttiX/2~
{ `w]s;G[
this("",0); '` pDngX
} <~ Sz04
7)s^8+
"~D]E7Q3y
public FileAccessI(String sName,long nPos) throws IOException r$2P;Cxj
{ AhZ8 0!
oSavedFile = new RandomAccessFile(sName,"rw"); N!g9*Z
this.nPos = nPos; tKpmm`2
oSavedFile.seek(nPos); Nm|!#(L
} `ho1nY$)CE
O%FPS=
0qX3v<+[6
public synchronized int write(byte[] b,int nStart,int nLen) Th=eNL]
{ lV%N
int n = -1; hiQha5
try{ V7/I>^X
oSavedFile.write(b,nStart,nLen); aG^4BpIP
n = nLen; iezO9`
} gG/!,Q.Qh
catch(IOException e) Yb E-6|cz
{ EW3(cQbK
e.printStackTrace (); k1QpKn*
} y-1 pR
j$+nKc$
V,$0p1?J
return n; ]Ux<aiY]a
} 5H ue7'LS
b#X^=n2
>Q(3*d >
} 3+XOZh8
)b:7-}d
Zl*X?5u
/* KQ~i<1&j
**SiteInfoBean.java rb|U;)C
*/ %"P,1&\^
package NetFox; X-wf:h?i
iRrl^\qn
}I :OsAw
public class SiteInfoBean { XHK70: i
^/r7@:
WVI{oso#
private String sSiteURL; //Site's URL -?0qf,W.
private String sFilePath; //Saved File's Path yxH ( c
private String sFileName; //Saved File's Name ?Orxmxc 2
private int nSplitter; //Count of Splited Downloading File t2lS ~l)
RO.k]x6
o#skR4lwe
public SiteInfoBean() Rb.SY{}C
{//nSplitter的缺省值为5 g[3)P+
//default value of nSplitter is 5 9^j &VmF
this("","","",5); _A=$oVe
} ~m$Y$,uH
)gMG#>up@
~P@Q7T*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {HCzp,Y
{ a]MX)?
sSiteURL= sURL; DK$s&zf
sFilePath = sPath; $fzaPD4.
sFileName = sName; f\jLqZY
this.nSplitter = nSpiltter; e:5bzk!~
xftBSdVE
mVy|{Oh
} }b-g*dn]5
QnJZr:4b
2K3{hxB
public String getSSiteURL() s{$(*_
{ D ^x-^6^
return sSiteURL; w/kt3Lw
} I= &stsH
6*3.SGUY
RS^lKJ1 U
public void setSSiteURL(String value) L>3x9
{ eN^qG 42
sSiteURL = value; 43@{JK9G
} /\hzb/
(Kv#m 3~
m8o(J\]
public String getSFilePath() ]]*7\ :cb
{ %;rHrDP(>
return sFilePath; *#C+iAF|)'
} lk( }-
WUh$^5W
h"/<?3{
public void setSFilePath(String value) Zd')57{
{ 1#ft#-g}
sFilePath = value; @9lUSk^9
} P9vA7[
#':fkIYe'
{62n7'U{
public String getSFileName() z&fwE$Nm
{ fP(d8xTx2y
return sFileName; m+Rv+_R
} K[!&b0O
s[w6FXt
;oc&Hb
public void setSFileName(String value) "\3B^ e,
{ D>LZP!
sFileName = value; ;<(W% _
} *^:N.&]
\Z+z?K O
#3+!ee27#
public int getNSplitter() FSA1gAW6g
{ '7iSp=
return nSplitter; )3>hhuaa
} {qN 5MsY
c1E'$- K@
6x%h6<#xh*
public void setNSplitter(int nCount) |\7 ET[Xq
{ ,&R/4:I
nSplitter = nCount; -}KC=,]vh
} SN1}xR$
} Z7=`VNHc
`.i!NBA'6
xo7Kn+ Kl
/* `|ASx8_!
**Utility.java 1*@'-mj
*/ "CI=`=
package NetFox; !0vG|C;'
uA#P'?
T-U}QM_e
public class Utility { 'LO^<
:gep:4&u
xo&]$W8
public Utility() $7rq3y
{ }#&#^ B#?O
v#U"pn|M
/(.mp<s0
} sXD1C2o
E.Jkf\
//线程睡眠 QmCe>+
public static void sleep(int nSecond) n}!PO[m~
{ !& z(:d
try{ .MP !`
Thread.sleep(nSecond); .P7"e5ge
} =5(>q5Z*
catch(Exception e) mqSQL}vR
{ @Bf%s(Uj+
e.printStackTrace (); ?'KL11@R
} @NNq z
} SV~cJ]F
#0y)U;dA+w
//日志 \cUC9/ b
public static void log(String sMsg) VB,?Mo}R
{ 4}eepJOn
System.err.println(sMsg); qa0 yg8,<
} mjKS{
Yd#/1!A7u
{l/-LZ.
public static void log(int sMsg) hHT_V2*
{ z$?~Y(EY
System.err.println(sMsg); f]\CD<g3|E
} <U!`J[n%
} 4Za7^c.
8&)DE@W
WRrd'{sB
/* vJ-q*qM1
**TestMethod.java ~;#Y9>7\\'
*/ 6y9t(m
package NetFox; !g(KK|`,m
3tZ]4ms}
98uV6b~g
public class TestMethod { 2gCX}4^3b
'8{Ne!y
-\ EP.Vtz
public TestMethod() +/)#( j@
{ ///xx/weblogic60b2_win.exe S|]X'f
try{ b-{=s+:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (4dhuT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TwVlg;
SiteFileFetch fileFetch = new SiteFileFetch(bean); \<y#R~7s
fileFetch.start(); ?MgUY)X
} \\u<S=G
catch(Exception e){e.printStackTrace ();} S&b*rA02zp
\4-"L>
A8oo@z68n>
} +gJ8{u!=k
o!{w"K
2M68CE
public static void main(String[] args) 7]||UuF<
{ 'Pn3%&O$
new TestMethod(); {:]9Q Tq
} e=.njMqW5
} Od5JG .]
点击下载更多相关资料