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)); Elom_
} ~Z=Q+'Hu0
for(int i=0;i<nEndPos.length-1;i++) Z7V1e<E
{ %S. _3`A
nEndPos = nStartPos[i+1]; <2fZYt vt
} q$yTG!q*
nEndPos[nEndPos.length-1] = nFileLength; qdx(wGG
} ,@;",
} N41)?-7F
}Cvf[H1+
7ykpDl^@
//启动子线程 jav7V"$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kOfbO'O9
for(int i=0;i<nStartPos.length;i++) q3z<v:=1y
{ LS}u6\(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5hr$tkkL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MXh0a@*]
nStartPos,nEndPos,i); ||;V5iR:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0>6J-
fileSplitterFetch.start(); @a'Rn
} &F +hh{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hQDl&A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R"QWap}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f<@`{oP@
nEndPos = " + nFileLength); X""}]@B9z
// fileSplitterFetch[nPos.length-1].start(); 6^nxw>-
4n.EA,:g:(
L4Si0 K
//等待子线程结束 4[K6ZDBU
//int count = 0; 5VlF\-
//是否结束while循环 Vj_z"t7q
boolean breakWhile = false; T'VKZ5W
)`m/vYKWL
qTnk>g_oS&
while(!bStop) K.6xNQl{}
{ :D=y<n;S+
write_nPos(); t$*CyYb{@
Utility.sleep(500); y1Yrf,E m=
breakWhile = true; Hp3T2|uL
X(K5>L>
)<%IY&\
for(int i=0;i<nStartPos.length;i++) b_oUG_B3]
{ "H)D~K~*
if(!fileSplitterFetch.bDownOver) z)pp{
{ rh(77x1|(G
breakWhile = false; ZRoOdo94
break; M{U7yE6*j*
} MY>o8A
} u-~?ylh
if(breakWhile) @!Q\| <
break; ZN(@M@}
I~7eu&QZ
&?yVLft
//count++; irzWk3@:
//if(count>4) o!|TCwt
// siteStop(); n6 AP6PK7
} b/'RJQSAc
q,_ 1?A)
/%h<^YDBf
System.err.println("文件下载结束！"); ITEd[ @^d
} :8Jn?E (36
catch(Exception e){e.printStackTrace ();} }G[Qm2k
} 7_AcvsdW
~ny4Ay$#
EX,)MU
//获得文件长度 HVcd< :g0
public long getFileSize() uVV;"LVK~
{ <*74t%AJ%
int nFileLength = -1; -$_h]x* W
try{ n/-d56
URL url = new URL(siteInfoBean.getSSiteURL()); ZG)%vB2c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 28PT19&
httpConnection.setRequestProperty("User-Agent","NetFox"); Q::6|B,G
}\)O1
twJ)h :!_y
int responseCode=httpConnection.getResponseCode(); ?hwT{h
if(responseCode>=400) '-m )fWf
{ 6/eh~ME=
processErrorCode(responseCode); F;_L/8Ov1
return -2; //-2 represent access is error ?W4IAbT\G
} :g=z}7!s
Ym"Nj
-+=+W
String sHeader; K~Hp%.
@-Js)zcl q
<hbxerg
for(int i=1;;i++) MUU9IMFJ
{ dzPwlCC%-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ok&u4'<
//Utility.log(in.readLine()); w6[uM%fHG
sHeader=httpConnection.getHeaderFieldKey(i); #97w6,P+
if(sHeader!=null) f_GqJ7Gk]
{ 6@@J>S>
if(sHeader.equals("Content-Length")) H{3A6fb<
{ :3Hr:~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wWR9dsB.;
break; @9<MW
} `FL!L59nz
} RtVG6'Y
else hZ@Wl6FG;
break; #x;i R8^
} 3mnq=.<(w
} {`vv-[j|
catch(IOException e){e.printStackTrace ();} (lY<\l
catch(Exception e){e.printStackTrace ();} ^}4=pkJ;s
Ju"*>66
J_^Ml)@iy
Utility.log(nFileLength); PI0[
+TnRuehtk
%XieKL
return nFileLength; G&/RJLX|w
} l|P(S(ikh
HO(9)sK
U^$o<2
//保存下载信息（文件指针位置） *@2?_b}A ^
private void write_nPos() m# ]VdO'f
{ `:XrpD
try{ v&GBu
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8s_'tw/{
output.writeInt(nStartPos.length); ovn)lIs
for(int i=0;i<nStartPos.length;i++) 3tlA!e
{ ."m2/Ks7
// output.writeLong(nPos); hDJ84$eVZ
output.writeLong(fileSplitterFetch.nStartPos); E%vG#
output.writeLong(fileSplitterFetch.nEndPos); D20n'>ddg
} E|jbbCZy2
output.close(); KC-q]
} P+Ta|-
catch(IOException e){e.printStackTrace ();} (Wu_RXfCw_
catch(Exception e){e.printStackTrace ();} cDS6RO?
} W/m,qilQI
KXP^F6@l
):lq}6J#
//读取保存的下载信息（文件指针位置） (&U8NeWZ
private void read_nPos() {Y! -]_5
{ 8N|y
try{ $6a55~h|(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =sk]/64h``
int nCount = input.readInt(); eVZ/3o
nStartPos = new long[nCount]; b{KpfbxcI
nEndPos = new long[nCount]; \i-HECc"U
for(int i=0;i<nStartPos.length;i++) (@H'7,
{ )h0F'MzW
nStartPos = input.readLong(); *LbRLwt
nEndPos = input.readLong(); Ih]'OaE
} I-Ya#s#m
input.close(); `eat7O
} Vb`m3
catch(IOException e){e.printStackTrace ();} a~_5N&~pi
catch(Exception e){e.printStackTrace ();} OA??fb,b
} BiQ7r=Dd.
!dVth)UV
9I:H=5c
private void processErrorCode(int nErrorCode) {U&*8Q(/
{ 3rEBG0cf]
System.err.println("Error Code : " + nErrorCode); ugtb`d{ Sl
} u~,@Zg87
5__8+R
<B*}W2\
//停止文件下载 p xrd D7
public void siteStop() p2;-*D
{ xe;1D'(
bStop = true; VemgG)\
for(int i=0;i<nStartPos.length;i++) fT-yY`
fileSplitterFetch.splitterStop(); e5_:15%R\
tc%?{W\
}>\+eG
} %G& Zm$u=
} !Qu)JR
//负责部分文件的抓取 :_%
**FileSplitterFetch.java iD)R*vnAi
*/ ^@'LF T)
package NetFox; e'I13)
jjgjeY
w1-/U+0o
import java.io.*; -,t2D/xK
import java.net.*; |@]`" k
}%B^Vl%ZZ
~G!>2 +L
public class FileSplitterFetch extends Thread { L=u>}?!,Fj
UC)-Fd
72qbxPY13h
String sURL; //File URL f>Mg.9gJ(
long nStartPos; //File Snippet Start Position 51Yq>'8
long nEndPos; //File Snippet End Position yp=(wcJ
int nThreadID; //Thread's ID D&f(h][hH?
boolean bDownOver = false; //Downing is over }4PIpDL
boolean bStop = false; //Stop identical }| BnG"8
FileAccessI fileAccessI = null; //File Access interface xeqAFq=9?
^[{\ZX
m"P"iK/Av(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5Uc!;Gd?b
{ 9|Cu2
this.sURL = sURL; w\U fq
this.nStartPos = nStart; }VlX!/42
this.nEndPos = nEnd; /jdq7CF
nThreadID = id; B1]dub9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `Z*k M VN
} hfpSxL
SrPZ^NF
-MrEJ
public void run() 0#~e KFy
{ FpjpsD~Qu
while(nStartPos < nEndPos && !bStop) Aen)r@Y:
{ U$j*{`$4
W8:?y*6
iq>PN:mr
try{ i?uJ<BdU[
URL url = new URL(sURL); SG1fu<Q6J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t&+f:)n
httpConnection.setRequestProperty("User-Agent","NetFox"); "oX@Z^
String sProperty = "bytes="+nStartPos+"-"; ?Xscc mN
httpConnection.setRequestProperty("RANGE",sProperty); #!d@;=[\
Utility.log(sProperty); Jrp{e("9
oR'8|~U@B
-7:J#T/\
InputStream input = httpConnection.getInputStream(); |cwGc\ES
//logResponseHead(httpConnection); 1*{` .
|tC`rzo
tL68 u[
byte[] b = new byte[1024]; U$R+&@;
int nRead; K4]c
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9/[3xhB4
{ qkpnXQ
nStartPos += fileAccessI.write(b,0,nRead); Ur`Ri?
//if(nThreadID == 1) ob=GB71j55
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f!;4-.p`
} [U_Su,
ViqcJD
.,t"iC:E
Utility.log("Thread " + nThreadID + " is over!"); "V!y"yQ
bDownOver = true; H"8fnN=xB
//nPos = fileAccessI.write (b,0,nRead); qy1$(3t$
} q.6$-w
catch(Exception e){e.printStackTrace ();} @}:}7R6
} nd(O;XBI
} Ay'2!K,I
u(B0X=B
V_JM@VN}Kk
//打印回应的头信息 t0XM#9L
public void logResponseHead(HttpURLConnection con) Xk[;MZ[
{ 1<RB}M
for(int i=1;;i++) n5i#GvO^
{ MsMNP[-l
String header=con.getHeaderFieldKey(i); ^v.~FFK
if(header!=null) X(F2 5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W]p)}#FR
Utility.log(header+" : "+con.getHeaderField(header)); 0\f3La
else pj.}VF!d
break; Bd$i%.r
} @RW=(&<1
} eC:?j`H-
z_vFf0
6T>e~<^
public void splitterStop() zmvF#o
{ .Ua|KKK C
bStop = true; xh[De}@
} 5 3=zHYQ
{e4`D1B
:4]^PB@dl
} 8 ;oU{
zmk#gk2H
JiL%1y9|
/* Pl4$`Qw#y
**FileAccess.java OM,-:H,
*//文件访问(定位，写) B>, O@og
package NetFox; Op^r}7
import java.io.*; $OK}jSH*v)
%lsk>V
J{"<Hgb
public class FileAccessI implements Serializable{ )N!-g47o%#
]Z?$ 5Ks
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~3bn?'`
RandomAccessFile oSavedFile; Jsf-t
long nPos; :e1BQj`R
$CXKeWS=Q.
-gZI^EII
public FileAccessI() throws IOException U JO
{ $y~!ePKh
this("",0); i,jPULzyjk
} B\BxF6 y
^W-03
,Q~C F;qe
public FileAccessI(String sName,long nPos) throws IOException ^i}*$ZC72
{ _&s37A&\
oSavedFile = new RandomAccessFile(sName,"rw"); O4xV "\
this.nPos = nPos; `4E6&&E+S
oSavedFile.seek(nPos); w@U`@})r.
} o<T_Pjp
L=zt\L
e>W}3H5w0
public synchronized int write(byte[] b,int nStart,int nLen) zRDBl02v$T
{ -z%| Jk
int n = -1; =bm<>h7.)
try{ 03aa>IO
oSavedFile.write(b,nStart,nLen); 9 z_9yT
n = nLen; O+U9 p
} C]{:>= K
catch(IOException e) r9@4-U7v&
{ xB=~3
e.printStackTrace (); ~$7fU
} .0$$H"t
.<8kDyim
<=KtRE>$
return n; 5N=QS1<$5
} ?ysC7((
KrNu7/H
NIn#
} Qx,jUL#2
Dk&@AjJga
PS ,@ \
/* G|5M~zP
**SiteInfoBean.java p]z *
*/ XBi}hT
package NetFox; Gb]t%\
nRKh|B)
4?GW]'d
public class SiteInfoBean { W|S{v7[l
Cf#[E~24
(dl7+
private String sSiteURL; //Site's URL Y>}[c
private String sFilePath; //Saved File's Path *,Bo $:(n
private String sFileName; //Saved File's Name zX+NhTTB
private int nSplitter; //Count of Splited Downloading File [43:E*\$
^F@z+q
/DPD,bA
public SiteInfoBean() +[$d9
{//nSplitter的缺省值为5 5e^t;
//default value of nSplitter is 5 0zR4Kj7EE
this("","","",5); EN^C'n
} A*)G. o:
A8bDg:G1i
Vo*38c2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]=T`8)_r)
{ [0v`E5
sSiteURL= sURL; 7Ddo^Gtx
sFilePath = sPath; 9z)p*+rUK
sFileName = sName; R{zAs?j
this.nSplitter = nSpiltter; ,[6N64fy
no_(J>p^&
#Fx$x#Gc@y
} v`i9LD0(
:]&O
KtWn08D!
public String getSSiteURL() 5(F @KeH>
{ Dk$[b9b
return sSiteURL; :_R[@?c
} X.)caF^j
fh rS7f'Zd
|q&&"SpA
public void setSSiteURL(String value) 59eq"08
{ P{qi>FJqe
sSiteURL = value; 4RgEN!d?H
} L~nVoKY*V
,1-n=eTQ
EC*rd
public String getSFilePath() r=8(n<;Co
{ V[&4Km9C
return sFilePath; t#pF.!9=
} x[]}Jf{t
(+Ia:D
D@5Ud)_
public void setSFilePath(String value) ,dhSc<:LT
{ i}C9
sFilePath = value; hq}kAv4B=
} >0yx!Iao
YcJZG|[
|TCHPKN
public String getSFileName() 6|q\ M
{ Qs24b
return sFileName; NYS|fa
} rdK=f<I]
}:NE
2, bo
public void setSFileName(String value) :CH?,x^!@
{ !?t#QDo
sFileName = value; dW hU o\>=
} >l|ao&z>bm
".Lwq_
F/BB]gUB
public int getNSplitter() 5r#0/1ym!
{ EA@p]+P
return nSplitter; 7GN>o@t
} O>P792)
)TNAgTmqK
@f<q&K%FJ
public void setNSplitter(int nCount) :__z?<?(
{ KW^#DI6tr
nSplitter = nCount; qY^OO~[
} pwq a/Yi
} &PJ&XTR
=pQ'wx|>|
Uy8r !9O
/* [l;9](\8O
**Utility.java >z&|<H%
*/ ,^]yU?eU
package NetFox; >fCz,.L
kNW}0CDgs
U Ke!zI
public class Utility { 3yT7;~vPj
tPDd~fOk
>hg?!jMjrr
public Utility() udCum4
{ P.G`ED|K!Y
,Mt/*^|
~zEBJgeyh
} Qx$CoY
@9yY`\"ed
//线程睡眠 9 F"2$;
public static void sleep(int nSecond) &O0@)jIV
{ I)@b#V=
try{ x.d;7
Thread.sleep(nSecond); |UA)s3Uhxb
} .nXOv]
catch(Exception e) `tmd'
{ $w,&h:.p
e.printStackTrace (); 85$W\d
} ``l7|b jJ
} |7 .WP;1
JA .J~3
//日志 v;!f
public static void log(String sMsg) $kc*~V~
{ >5,nB<
System.err.println(sMsg); 5W UM"eBwL
} -b?yzg,8
)ad-p.Hus
<F~0D0G
public static void log(int sMsg) ^ +e5 M1U=
{ ~,199K#'
System.err.println(sMsg); U _QCe+
} I/F3%'O
} dd$}FlT
Vn4y^_H
=!@5!
/* gO{XD.s
**TestMethod.java >P@JiR<@\n
*/ ^o`;C\
package NetFox; *b< a@
v/\in'H~
X-xN<S q
public class TestMethod { JYE[ 1M
L.5 /wg
8SJi~gV
public TestMethod() j?5s/
{ ///xx/weblogic60b2_win.exe C(t>ZR
try{ }ioHSkCD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g\Ck!KJ/y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -+#QZ7b
SiteFileFetch fileFetch = new SiteFileFetch(bean); bV'^0(Zv
fileFetch.start(); %TOYU(k
} X`REhvT
catch(Exception e){e.printStackTrace ();} @wzzI 7}C
'a}<|Et.
82mKI+9&"
} //[zUn
ENmfbJ4d~
v6Vd V.BI
public static void main(String[] args) h x_,>\@
{ p5 !B
new TestMethod(); 4P1<Zi+<
} epWTZV(1x
} H)eecH$K
点击下载更多相关资料