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)); xCtmXo
} E}ZJ)V7
for(int i=0;i<nEndPos.length-1;i++) 0:b2(^]bg
{ RVeEkv[qp
nEndPos = nStartPos[i+1]; _/O25% l
} Ge<nxl<Bd
nEndPos[nEndPos.length-1] = nFileLength; @]ao"ui@/
} : "1XPr
} a+Ac[>
wgw(YU
'R_g">B.
//启动子线程 LQjsOo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !A%<#Gjt
for(int i=0;i<nStartPos.length;i++) +a*tO@HG
{ \G-KplKS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &~W:xg(jN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cH>%r^G\
nStartPos,nEndPos,i); l<N}!lG|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ."FuwKSJCo
fileSplitterFetch.start(); KIWe@e
} %dY<=x#b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xNbPsoK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &iV,W4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o^ XtU5SVq
nEndPos = " + nFileLength); []D@Q+1
// fileSplitterFetch[nPos.length-1].start(); [p<w._b i
^yOZArc'r
F;]%V%F.X
//等待子线程结束 -a-(r'Qc(
//int count = 0; @*sWu_-Y%
//是否结束while循环 =%/)m:f!^
boolean breakWhile = false; YIjTL!bA"
GI&h`X5,e
KVJ_E!i
while(!bStop) y99mC$"Ee`
{ #B\"'8#
write_nPos(); !50[z:
Utility.sleep(500); IC7M$
breakWhile = true; [Vma^B$7Vj
qT^I?g"!
Ng_!zrx04
for(int i=0;i<nStartPos.length;i++) ,2W8=ON
{ rvw)-=qR[
if(!fileSplitterFetch.bDownOver) hvaSH69*m
{ 5;HH4?]p
breakWhile = false; hodgDrmO/
break; |vw"[7_aS
} B $mX3B+a
} K1T4cUo
if(breakWhile) )vSRHE
break; 5D'\b}*lJ}
k`N^Vdr
5s]. @C8
//count++; >:b Q
//if(count>4) @/31IOIV]`
// siteStop(); ^- d%r
} sQ\8>[]
*Em,*!
^N)R=tl
System.err.println("文件下载结束！"); tdu$pC6
} p}~qf
catch(Exception e){e.printStackTrace ();} 1aTB%F
} :*KHx|Q
_FWBUZ;N
U-3i
//获得文件长度 [)TRTxFb
public long getFileSize() .Fp4: e
{ N}t 2Nu-
int nFileLength = -1; Ll4g[8
try{ 5bgs*.s
URL url = new URL(siteInfoBean.getSSiteURL()); sL$:"=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )<tI!I][j
httpConnection.setRequestProperty("User-Agent","NetFox"); zld#qG6
\vO,Ee~#W
5yz(>EVH
int responseCode=httpConnection.getResponseCode(); _BP&n
if(responseCode>=400) ;N?]eM}yf
{ p|p l
processErrorCode(responseCode); 53n^3M,qK
return -2; //-2 represent access is error ;67x0)kn
} LBZ+GB
AnX%[W "
e\:+uVzz
String sHeader; [wzb<"kW
s|y "WDyx5
z.;ez}6%V
for(int i=1;;i++) 71t*%
{ lp^<3o*1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u@cYw:-C
//Utility.log(in.readLine()); #*UN >X
sHeader=httpConnection.getHeaderFieldKey(i); Rw0qcM\>|
if(sHeader!=null) |3KLk?2
{ ^0\
if(sHeader.equals("Content-Length")) ?m\t|/0Q
{ aq@8"b(.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #$8% w
break; ",KCCis
} @y\XR
} i=oU;7~zK
else )`O~f_pIC
break; )O@]uY
} VL` z[|e @
} ia+oX~W!VR
catch(IOException e){e.printStackTrace ();} Su/6Q$0 t
catch(Exception e){e.printStackTrace ();} N@Uy=?)ZJ
LAS'u"c|
IHv[v*4:
Utility.log(nFileLength); 9^#c| 0T
Evg_q>
Eu@huN*/
return nFileLength; S(*sw 0O@+
} %_%Q8,W
.Z `av n
hRD=Y<>A
//保存下载信息（文件指针位置） :Ra,Eu
private void write_nPos() Xx0hc 8qd
{ .7avpOfz
try{ #PH~1`vl
output = new DataOutputStream(new FileOutputStream(tmpFile)); lHPd"3HDK
output.writeInt(nStartPos.length); ORJIo
for(int i=0;i<nStartPos.length;i++) 1e{IC=
{ ij(B,Y
// output.writeLong(nPos); TU,s*D&e
output.writeLong(fileSplitterFetch.nStartPos); @v)p<r^M">
output.writeLong(fileSplitterFetch.nEndPos); :2rZcoNb.
} q(.sq12<<W
output.close(); 3 09hn
} I%j|D#qY:T
catch(IOException e){e.printStackTrace ();} PIoLywpRn
catch(Exception e){e.printStackTrace ();} 87 $dBb{
} .yqM7U_
&;[Io
gv-xm
//读取保存的下载信息（文件指针位置） Rnr(g;2
private void read_nPos() sHt].gZ
{ y[)>yq y
try{ ?R$F)g7<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qzKdQ&vO
int nCount = input.readInt(); uXJ;A *
nStartPos = new long[nCount]; vZaZc}AyL
nEndPos = new long[nCount]; U4C 9<h&
for(int i=0;i<nStartPos.length;i++) 2a`o &S
{ EIf5(/jo
nStartPos = input.readLong(); kwo3`b
nEndPos = input.readLong(); KyYMfC
} $0>60<J
input.close(); %7IugHH9y
} K}buH\yco
catch(IOException e){e.printStackTrace ();} T?tgdJ
catch(Exception e){e.printStackTrace ();} yW1)vD7
} /_AnP
4C61GB?Vy
IoQEtA
private void processErrorCode(int nErrorCode) z<U-#k7nz
{ !sQY&*
System.err.println("Error Code : " + nErrorCode); +eK"-u~K
} aW)-?(6>
mD$A4Y-'p
>~[c|ffyo/
//停止文件下载 H8Bs<2
public void siteStop() :t8b39
{ s%nUaWp~
bStop = true; %et }A93
for(int i=0;i<nStartPos.length;i++) .oYl-.E>&
fileSplitterFetch.splitterStop(); Sq/ qu-%X
=jOv] /
`.~N4+SP
} Rg\z<wPBG
} fk6%XO
//负责部分文件的抓取 Pq;U&,
**FileSplitterFetch.java )wam8k5
*/ fTS5yb%
package NetFox; r@h5w_9
q<[P6}.
zZPuha8
import java.io.*; ;qafT@ }C
import java.net.*; .h@rLorm>
"7'J&^|
~dgDO:)
public class FileSplitterFetch extends Thread { 0QXVW}`hz
"}u.v?HYz
qT{U(
String sURL; //File URL 8uc1iB
long nStartPos; //File Snippet Start Position 591>rh)
long nEndPos; //File Snippet End Position VRWAm>u
int nThreadID; //Thread's ID 5nv#+ap1 "
boolean bDownOver = false; //Downing is over :|V$\!o'U
boolean bStop = false; //Stop identical ieDk;
FileAccessI fileAccessI = null; //File Access interface ddJQC|xR}
#%a;"w
&gVN&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dt \TQJc~
{ 0%9 q8M;
this.sURL = sURL; nhB1D-
this.nStartPos = nStart; p `8s
this.nEndPos = nEnd; @Lpq~ 1eZB
nThreadID = id; 8'r2D+Vwm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [-65PC4aN
} ~P*6ozSYpY
hm84Aq= f
|{BIHgMh
public void run() 8##-EN;ag
{ #a/5SZP Z\
while(nStartPos < nEndPos && !bStop) 8{wwd:6
{ kw>v:F<M
W]"zctE
Tzt8h\Q^z
try{ )M,OfXa
URL url = new URL(sURL); 63q^ $I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]e"=$2d$
httpConnection.setRequestProperty("User-Agent","NetFox"); f/ ?_
String sProperty = "bytes="+nStartPos+"-"; 9_q#W'/X
httpConnection.setRequestProperty("RANGE",sProperty); (Mo*^pVr
Utility.log(sProperty); HmiR.e%<b
^1S!F-H4\
0t^M3+nc
InputStream input = httpConnection.getInputStream(); ?J%1#1L"/
//logResponseHead(httpConnection); 7]U"Z*
h;C5hU4P
35Ij ..z0
byte[] b = new byte[1024]; 54gBJEhg
int nRead; 1Ce@*XBU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yQ_B)b
{ H7z,j}l
nStartPos += fileAccessI.write(b,0,nRead); )JDs\fUE
//if(nThreadID == 1) 09X01X[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,V,`Jf
} ^!<U_;+
I?h)OvWd
!^^?dRd*v
Utility.log("Thread " + nThreadID + " is over!"); L6t+zIUc-~
bDownOver = true; Vi>,kF.fV
//nPos = fileAccessI.write (b,0,nRead); TTeH`
} n&{Dq}q
catch(Exception e){e.printStackTrace ();} {'XggI%
} R?GDJ3
} gQo]
;\a YlV-
%7"q"A r[
//打印回应的头信息 _BM" ]t*
public void logResponseHead(HttpURLConnection con) Ee)T1~;W
{ >QjAoDVX?
for(int i=1;;i++) X}=n:Ql'YY
{ ^`*9QjY
String header=con.getHeaderFieldKey(i); 3)F|*F3R
if(header!=null) =!kk|_0%E
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M`. tf_x
Utility.log(header+" : "+con.getHeaderField(header)); !S^AgZ~
else G<At_YS
break; 0C =3dnp6
} v/Py"hQ
} 1{r3#MVL
3/aMJR:o
x*![fK
public void splitterStop() ~3Lg"I
{ i'a?kSy
bStop = true; .\[`B.Q
} xAqb\|$^
w zYzug
K0H'4' I
} Of-Rx/
p6]7&{>
E.r>7`E
/* "8c@sHk(w
**FileAccess.java $&y%=-]|
*//文件访问(定位，写) T?:Rdo!:u
package NetFox; u5O+1sZ"6
import java.io.*; GS0;bI4ay
o}$XH,-9&
9)y/:sO<P
public class FileAccessI implements Serializable{ _76PIR{an
yL%K4$z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y-T| #
RandomAccessFile oSavedFile; ^M3~^lV
long nPos; )`SES."
!Nu<xq@!
zAK+8{,
public FileAccessI() throws IOException {!.(7wV\
{ VO,!x~S!
this("",0); RS"H8P4W
} e>7]w,*|
u}>#Eb
)'Oh`$M
public FileAccessI(String sName,long nPos) throws IOException $56Z#'(D
{ V_C-P[2~
oSavedFile = new RandomAccessFile(sName,"rw"); AjmVc])
this.nPos = nPos; ^@I
oSavedFile.seek(nPos); Ao&\EcIOT
} G'rxXJq
3;)>Fs;
IM:=@a{
public synchronized int write(byte[] b,int nStart,int nLen) |M>eEE*F<
{ 6BY-^"W5`
int n = -1; !(mjyr
try{ K\>tA)IPSV
oSavedFile.write(b,nStart,nLen); kd=GCO
n = nLen; __`*dL>*
} b_,|>U
catch(IOException e) *YW/_
{ 8;z6=.4xtg
e.printStackTrace (); IYqBQnX}oM
} @En^wN
g3Ec"_>P
Mx6@$tQ%
return n; M^MdRu
} l*ayd>`~x
\qR7mI/*
`Y BC
} INcg S MM
X- pqw~$
7q?9Tj3
/* F|F]970
**SiteInfoBean.java ICuF %
*/ P1zKsY,l$<
package NetFox; rW0kA1=E
ZZWD8AX
cnSJ{T
public class SiteInfoBean { sqla}~CiX
'HT7_$?*
P.6nA^hXB
private String sSiteURL; //Site's URL 5 elw~u
private String sFilePath; //Saved File's Path E_Im^a
private String sFileName; //Saved File's Name 8 ![|F:
private int nSplitter; //Count of Splited Downloading File ,O.3&Nz,c
CJ(NgYC h
'/`= R
public SiteInfoBean() eKgisY4#
{//nSplitter的缺省值为5 y@ ML/9X8q
//default value of nSplitter is 5 7]^M>#
this("","","",5); (>F%UY
} SLO%7%>p
6Ca(U'
C2@,BCR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ol1e/Wv
{ nFE4qm
sSiteURL= sURL; =3|O%\
sFilePath = sPath; c05TsMF&O
sFileName = sName; -%2[2p
this.nSplitter = nSpiltter; ;ToKJ6hN|*
HuB<k3#sPy
S7=Bd[4
} q+P|l5_ t
aT_&x@x
>fe-d#!{
public String getSSiteURL() umD!2 w
{ AP[|Ta
return sSiteURL; %R@X>2l/_
} 7+]=-
`^bgUmJ~
D-8O+.@
public void setSSiteURL(String value) thV>j9'
{ 6;C3RU]
sSiteURL = value; :q=%1~Idla
} #~SP)Ukp
1=#q5dZ]
/<E5"Mm%
public String getSFilePath() Ge,;8N88
{ Xua+cVc\y
return sFilePath; !vX D
} yMyE s8
7G.#O}).b
*&?c(JU;<
public void setSFilePath(String value) HU%o6cw
{ /b]oa!
sFilePath = value; vLR~'"`F
} *\=.<|HZ
~GTz:nC*
u@~JiiC%
public String getSFileName() 4$qWiG~
{ ELBa}h;
return sFileName; ,z3{u162
} "J+3w
~2<7ZtV=
'6Ay&A3N]
public void setSFileName(String value) CF+_/s#j^
{ 350_CN,
sFileName = value; u`y><w4i
} T6H}/#*tK
MxSM@3v(
)ap_Z6
public int getNSplitter() 3= xhoRX
{ /V8}eZ97
return nSplitter; \zieyE
} (Q%'N3gk
~\=1'D^6CK
7:9.&W/KE
public void setNSplitter(int nCount) /J04^6
{ ,S'p%g
nSplitter = nCount; XEn*?.e
} _{R=B8Zz\
} Jj,U RD&0R
G"X8}:}
R<sJ^nx
/* qtiz a~u
**Utility.java 4!+pc-}-
*/ _/Gczy4)#
package NetFox; V6t,BJjS
h.-@ F
~.A)bp
public class Utility { 5O~HWBX.
Mr?Xp(.}G
SV:4GVf
public Utility() HHq_P/'
{ G2t;DN(
{.Z}5K
5WC+guK7
} [|P!{?A43|
SG-'R1 J
//线程睡眠 }:u~K;O87
public static void sleep(int nSecond) FL(6?8zK
{ Y^ kXSU
try{ vFE;D@bz:
Thread.sleep(nSecond); ta`N8vnf
} $-#Yl&?z9
catch(Exception e) PUo/J~v
{ Q-MQ9'
e.printStackTrace (); X>NhZ5\
} 1WY/6[
} S/Fkw4%
2>86oP&
//日志 mjWU0Gh%*
public static void log(String sMsg) yHHt(GM|o
{ #{k|I$
System.err.println(sMsg); f>piHh?
} h3*Zfl<]
MF~H"D n
(q{Ck#+
public static void log(int sMsg) ZKQG:M~|
{ @;<ht c
System.err.println(sMsg); jV? }9L^;
} _Qh z3'I1
} ?T>'j mmV=
z;A>9vQ_J
R,9[hNHWGs
/* Row)hx8
**TestMethod.java 3 n'V\Hvz
*/ L]d-hs
package NetFox; ]Ar\c["
D8>enum
EI_
public class TestMethod { ?[)}l9
uiJS8(Cb
g.'yZvaP
public TestMethod() fv`O4
{ ///xx/weblogic60b2_win.exe x9x E&
try{ 87:!C5e}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5B&;uY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4hAl-8~Q6
SiteFileFetch fileFetch = new SiteFileFetch(bean); D\[h:8k
fileFetch.start(); ~er\~kp
} :>TEDy~O%
catch(Exception e){e.printStackTrace ();} &v"3*.org@
VH=S?_RY>
oS7(s
} \3'9Uz,OC
aX~%5mF
DyQM>xw)t
public static void main(String[] args) Wx~k&[&E
{ <{2e#Y
new TestMethod(); !-N6l6N
} M/):e$S
} ?0YCpn
点击下载更多相关资料