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)); By?nd)
} 7~wFU*P1
for(int i=0;i<nEndPos.length-1;i++) P>*Fj4Z~
{ R2}kz.
nEndPos = nStartPos[i+1]; /!=U+X
} }_{y|NW
nEndPos[nEndPos.length-1] = nFileLength; 5/B#)gm
} D:wnO|:
} onnI !
t_jyyHxoZ:
N[qA2+e$Z
//启动子线程 vG]GQ#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x37/cu
for(int i=0;i<nStartPos.length;i++) s0cs'Rg
{ nJFk4v4:2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .E+OmJwD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |7 &|>
nStartPos,nEndPos,i); u64@"P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #^|| ]g/N
fileSplitterFetch.start(); (n=9c%w
} !1a}| !Zn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -$+,]t^GV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j4;Du>obQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i@P9EU
nEndPos = " + nFileLength); <7=&DpjI7F
// fileSplitterFetch[nPos.length-1].start(); TC qkm^xv
O(VxMO
}@Xh xZu
//等待子线程结束 +J|+es
//int count = 0; i[$-_
//是否结束while循环 ]SFWt/<
boolean breakWhile = false; pw@`}cM=
]\A1mw-T
w#*/y?"D
while(!bStop) m8'@UzB
{ `-VG ?J
write_nPos(); w6vLNX
Utility.sleep(500); fO K|:
breakWhile = true; sffhPX\I
-i#J[>=w{C
-Q6(+(7_|
for(int i=0;i<nStartPos.length;i++) 9Ei5z6Vk/+
{ N99[.mErU
if(!fileSplitterFetch.bDownOver) ^_@r.y]
{ :<L5sp
breakWhile = false; /@VsqD
break; {'NBp0i
} ^^%JoQ.
} /K7Bae5h
if(breakWhile) v@VLVf)>9^
break; HLVQ7
&x`&03X
Qh*)pt]n
//count++; <mL%P`Jj
//if(count>4) `M&P[.9Pz
// siteStop(); 5J ySFG3
} j(j#0dXLh
[w!C*_V 9
G\R*#4cF
System.err.println("文件下载结束！"); ^w.]Hd2
} w&%9IJ
catch(Exception e){e.printStackTrace ();} 6Lb{r4^
} Hb+X}7c$
>Iuzk1'S
{@3z\wMK$
//获得文件长度 u$C\E<G^
public long getFileSize() :$Q`>k7A
{ 1Pm4.C)
int nFileLength = -1; V\0E=M*P
try{ jgG$'|s}
URL url = new URL(siteInfoBean.getSSiteURL()); u^t$cLIZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /hL\,x2
httpConnection.setRequestProperty("User-Agent","NetFox"); g0PT8]8
E, GN|l
Qlw>+y-i
int responseCode=httpConnection.getResponseCode(); ["u#{>(X
if(responseCode>=400) 58::h.:
{ OZf6/10O/
processErrorCode(responseCode); Zae.MO^C!
return -2; //-2 represent access is error k0JW[04j
} S<"oUdkz
%)?`{O~ h
zVw:7-
String sHeader; Or7 mD
EkjgNEXq
V43TO
for(int i=1;;i++) RND9D\7
{ V^WU8x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Fk{J@Y
//Utility.log(in.readLine()); {=67XrWN1
sHeader=httpConnection.getHeaderFieldKey(i); 8f|98T"
if(sHeader!=null) j C)-`_
{ l-<`m#/v
if(sHeader.equals("Content-Length")) Sm)u9
{ V7EQ4Om:It
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TN\|fzj
break; R:M,tL-l
} V,Q4n%h1.
} nBkh:5E5%
else O#)jr-vXdV
break; 49AW6H.JT
} ^XG*z?Tt
} `<U5z$^QTw
catch(IOException e){e.printStackTrace ();} #Y2i*:<
catch(Exception e){e.printStackTrace ();} f"dSr
2Q@Y^t
YHB9mZi
Utility.log(nFileLength); RO.U(T
D<>@ %"%
zU&L.+
return nFileLength; .XS9,/S
} ?2 f_aY ;
Z+4D.bA
dEp7{jY1O
//保存下载信息（文件指针位置） eM2|c3/
private void write_nPos() du_4eB
{ /&^W#U$4
try{ U>a\j2I
output = new DataOutputStream(new FileOutputStream(tmpFile)); cE\>f8 I
output.writeInt(nStartPos.length); 36vgX=}
for(int i=0;i<nStartPos.length;i++) @kxel`,$e
{ Dd,2;#_
// output.writeLong(nPos); r@kP*
output.writeLong(fileSplitterFetch.nStartPos); QI_4*
output.writeLong(fileSplitterFetch.nEndPos); A&"%os
} M'L;N!1A
output.close(); &%mXYj3y5
} xfFg,9w8
catch(IOException e){e.printStackTrace ();} }t%W1UJ
catch(Exception e){e.printStackTrace ();} (Un_!)
} NxA)@9Q
]uQqn]+I!
2=iH$v
//读取保存的下载信息（文件指针位置） ])}]/Qw
private void read_nPos() ?LK2g
{ IzLQhDJ1
try{ S DLvi!y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t#i,1aHA
int nCount = input.readInt(); n, i'Dhzk
nStartPos = new long[nCount]; )"+2Z^1-
nEndPos = new long[nCount]; T~:|!`
for(int i=0;i<nStartPos.length;i++) ep/Y^&$M
{ 0#cy=*E
nStartPos = input.readLong(); ]#2Y e7+
nEndPos = input.readLong(); /Q{P3:k
} .iD*>M:W
input.close(); OEx^3z^
} Z\}K{#
catch(IOException e){e.printStackTrace ();} C3NdE_E
catch(Exception e){e.printStackTrace ();} wU\s; dK
} fw6UhG
sarq`%zrk
U.!lTLjfLz
private void processErrorCode(int nErrorCode) 7R!5,Js+
{ jhbonuV_
System.err.println("Error Code : " + nErrorCode); e]=lKxFh&l
} ::FS/Y]Fg
B=8Iu5m
uvP2Wgt
//停止文件下载 #n0Y6Pr
public void siteStop() 5NoI~X=
{ V-'K6mn;
bStop = true; o]:3H8
for(int i=0;i<nStartPos.length;i++) r$Co0!.
fileSplitterFetch.splitterStop(); ';Zi@f"
\.YS%"Vz
1$qh`<\
} a<}#HfC;'
} o*U]v
//负责部分文件的抓取 )q7UxzE+
**FileSplitterFetch.java )XcOl7XLN
*/ e@:sR
package NetFox; {:@tQdM:i8
^WBuMCe
;qHOOT
import java.io.*; >D201&*G%
import java.net.*; EdZ\1'&/9
pvmC$n^zc
cuy1DDl
public class FileSplitterFetch extends Thread { S26MDLk`R3
Vz6Qxd{m3
Reatdh
String sURL; //File URL Jgnhn>dHe
long nStartPos; //File Snippet Start Position da)NK!
long nEndPos; //File Snippet End Position 6G=j6gK%P
int nThreadID; //Thread's ID M1KqY:9E
boolean bDownOver = false; //Downing is over -D6exTxh"
boolean bStop = false; //Stop identical vWGwVH/K
FileAccessI fileAccessI = null; //File Access interface r@ZJ{4\Q
kbM3
5mb]Q)f9-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EkziAON
{ jH_JmYd
this.sURL = sURL; BcI|:qv|
this.nStartPos = nStart; zOQ>d|p?X
this.nEndPos = nEnd; B^g ?=|{
nThreadID = id; q$=#A7H>3)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (<^yqH?
} w*R$o
8By|@LO
eq UME
public void run() h:9Zt0,
{ #8)*1?
while(nStartPos < nEndPos && !bStop) 6Fe34n]m
{ `r?7oxN
K4kMM*D
I_RsYw
try{ qgfi\/$6
URL url = new URL(sURL); o"*AtGR+"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YpqrZWvh
httpConnection.setRequestProperty("User-Agent","NetFox"); =ZqT3_
String sProperty = "bytes="+nStartPos+"-"; G;YrF)\
httpConnection.setRequestProperty("RANGE",sProperty); r?/'!!4
Utility.log(sProperty); Fi0GknQ+
EAM5{Nc
~c\e'&sc;
InputStream input = httpConnection.getInputStream(); RsYU59_Y
//logResponseHead(httpConnection); t<#h$}=:Vt
b9!FC$^J
WYr/oRO
byte[] b = new byte[1024]; BqT y~{)+
int nRead; *c2YRbU(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lv04g} W
{ soQ1X@"0
nStartPos += fileAccessI.write(b,0,nRead); >rf'-X4n
//if(nThreadID == 1) |j,"Pl}il^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =uS9JU^E
} ;n 7/O5M|
>Z5gSs0
:\|SQKD
Utility.log("Thread " + nThreadID + " is over!"); 9E6_]8rl
bDownOver = true; `E>1>'
//nPos = fileAccessI.write (b,0,nRead); [EKQR>s)
} "yS _s
catch(Exception e){e.printStackTrace ();} P}4QQw
} .4E&/w+
} .nVa[B|.
BBev<
T \_]^]>
//打印回应的头信息 9?SZNL['V
public void logResponseHead(HttpURLConnection con) U[ 0=L`0e
{ va0{>Dc+
for(int i=1;;i++) jEZMUqGY!
{ Rd#WMo2Xd
String header=con.getHeaderFieldKey(i); ojanBg
if(header!=null) Ys\Wj%6A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H*r)Z90
Utility.log(header+" : "+con.getHeaderField(header)); 4GX-ma,
else B\o Mn
break; C)`Fv=]R
} 85LAYaw
} z62;cv
j3{D^|0bP
eLfk\kk]Pc
public void splitterStop() XMxSQ B1
{ H<PtAYFS
bStop = true; tg<EY!WY
} q-}Fvel u
3v1iy/ /
UdpF@Q
} <4HDZ{"M
gMzcTmbc8
zdYy^8V|z
/* =\H!GT
**FileAccess.java d^{RQ
*//文件访问(定位，写) |Uc_G13Y{D
package NetFox; ~Vr.J}]J
import java.io.*; ;)D];u|_
Utnr5^].2O
^c9t'V`IWQ
public class FileAccessI implements Serializable{ CEX"D`
t.xxSU5~%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AP'*Nh@Ik(
RandomAccessFile oSavedFile; I|^;B8[
long nPos; {y=j?lD
K/IWH[
wk5s)%V
public FileAccessI() throws IOException Ab{ K<:l
{ W04@!_) <
this("",0); ahJ`$U4n
} n>BkTaI
Uq^#riq
zh8nc%X{
public FileAccessI(String sName,long nPos) throws IOException Vex{.Vh,"
{ Cv6'`",Yzm
oSavedFile = new RandomAccessFile(sName,"rw"); ;DFSzbF`
this.nPos = nPos; 21K>`d\
oSavedFile.seek(nPos); )48QBz?
} ;:\<gVi:
<G|(|E1
_`&m\Qe>
public synchronized int write(byte[] b,int nStart,int nLen) 1v.c 6~
{ Rwz0poG`WG
int n = -1; *U&0<{|T
try{ :~Wrf8UQ
oSavedFile.write(b,nStart,nLen); L^@'q6*}
n = nLen; J}v}~Cv
} \LR~r%(rM
catch(IOException e) 4T|b Cs?e
{ kmP]SO?tx
e.printStackTrace (); >=:&D)m"
} ILEz;D{]
2$+bJJM
WW4vn|0v
return n; v%+:/m1
} hT`J1nNt
O}-jCW;K
6jE|
} &Sw%<N*r
u0|8Tgf
}B\a<0L/
/* )dbB=OZ
**SiteInfoBean.java RJ 8+h
*/ f$e[u Er
package NetFox; 7puFz4+f
Dfg2`l
X[]m _@v
public class SiteInfoBean { 6Ypc`
Ql/cN%^j$
v$7QIl_/7
private String sSiteURL; //Site's URL ,?8qpEG~#+
private String sFilePath; //Saved File's Path ORe(]I`Z
private String sFileName; //Saved File's Name /uPcXq:L~
private int nSplitter; //Count of Splited Downloading File ?Y-%'J(
y{ibO}s
^1iSn)&
public SiteInfoBean() JEXy%hl
{//nSplitter的缺省值为5 l=S35og
//default value of nSplitter is 5 q rJ`1
this("","","",5); n.'8A(,r3
} O#:$^#j&
\F1_lq;K
C'\- @/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k1w_[w[
{ UQ)W%Y;[0
sSiteURL= sURL; 4|buk]9
sFilePath = sPath; >7lx=T x
sFileName = sName; 60P#,o@G
this.nSplitter = nSpiltter; `q}I"iS
zMbN;tu
i UCXAWP
} D!{Y$;
Xe6w|
~ {E'@MU
public String getSSiteURL() wvO|UP H\
{ MLw7}[
return sSiteURL; l~c@^!
} sGyeb5c
bLlKe50
~ELNyI11
public void setSSiteURL(String value) 2`7==?
{ GPkmf%FJ
sSiteURL = value; PDJr<E?
} H$=e -L`@
zKw`Md
.aO,8M
public String getSFilePath() !\zWF
{ ?5C!<3gM)
return sFilePath; LPZF)@|`
} V=R 3)GC
P\yDa*m
+o\:d1y
public void setSFilePath(String value) ah+~y,Gl
{ C7rNV0.Fq
sFilePath = value; E@@5BEB ~
} ]$ L|
'8Q]C*Z
+c(zo4nZ
public String getSFileName() rM`X?>iT+
{ iq8GrdL"
return sFileName; rSZd!OQ
} 'FqQzx"r
3.|S
.<jr0,i
public void setSFileName(String value) YPU*@l>
{ }#L^!\V}
sFileName = value; *@Lp`thq
} iP =V8g?L
d74d/l1*{
8$")%_1]
public int getNSplitter() 9!6f-K
{ j/R[<47
return nSplitter; zz+$=(T:M
} KC/=TSSXd.
(\\eo
r[2ILe
public void setNSplitter(int nCount) }Ga\wV
{ ?3nR
nSplitter = nCount; CnpV:>V=
} -8; 7Sp1
} bSiYHRH.e
#r#1JtT
O{QA
/* d;zai]]
**Utility.java `P@T$bC
*/ G/b^|;41
package NetFox; wG~`[>y (
3vuivU.3
"3Uv]F
public class Utility { LCZ\4g05
&|Bc7+/P
_y),J'W^3u
public Utility() tz5e"+Tz
{ W=j[V Oq
Cbg!:Cws
CLRiJ*U
} ZIf
5*j?E
//线程睡眠 wLi4G@jJ
public static void sleep(int nSecond) 3jGWkby0
{ Y'1S`.
try{ gbI^2=YT'
Thread.sleep(nSecond); mkYqpD7
} Sm)Ha:[4
catch(Exception e) hWM< 0=
{ mtJ9nC
e.printStackTrace (); x}_]A$nV
} z>XrU>}
} =T-&j60
xAK6pDp
//日志 lt ^GvWg
public static void log(String sMsg) FoNSM$x
{ 2/?`J
System.err.println(sMsg); mR&H9NG
} c#|raXGT
nH`Q#ZFz]?
{t0) q
public static void log(int sMsg) =7w\ 7-.m
{ 9Xj7~,
System.err.println(sMsg); 19HM])Zw\
} f({Ei`|
} {{B%f.
ix([mQg
q#T/
/* 01}C^iD
**TestMethod.java Q~OxH'>>(
*/ qCljo5Tq'
package NetFox; U@HK+C"M|
G`n_YH084
v:!Z=I}>
public class TestMethod { A;*d}Xe&J
S#MZV@nGF
GO__$%~
public TestMethod() ]!I7Y.w6
{ ///xx/weblogic60b2_win.exe $*AYcy7
try{ o$#G0}yn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2>cGH7EBD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qHuZcht
SiteFileFetch fileFetch = new SiteFileFetch(bean); v-#Q7T
fileFetch.start(); SSPHhAeH8
} rf?qdd(~cH
catch(Exception e){e.printStackTrace ();} .$qnZWcgG
<R''oEf9
F$ #U5}Q
} 1`(tf6op
vd[}Gd
]~aF2LJ_q
public static void main(String[] args) 8vMG5#U[
{ -*$HddD
new TestMethod(); L\@I*QP
} UJM1VAJ0
} V8rx#H~
点击下载更多相关资料