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)); d0I s|Gs
} K)LoZ^x0)
for(int i=0;i<nEndPos.length-1;i++) '1b 1N5~
{ ch0^g8@Q[
nEndPos = nStartPos[i+1]; )9yQ C
} =figat
nEndPos[nEndPos.length-1] = nFileLength; iLSUz j`
} /OztkThx=
} 3O$l;|SX
MZh.Xo
d5gwc5X
//启动子线程 ,ZJ}X 9$<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iptA#<Yj
for(int i=0;i<nStartPos.length;i++) n&;JW6VQS
{ X^eyrqv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~q566k!Ll!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !FP ]
nStartPos,nEndPos,i); }}TPu8Rl
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %;QK5L
fileSplitterFetch.start(); Z.gb'
} yg}O9!MJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j? BL8E'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^aAs=KditO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $EFS_*<X
nEndPos = " + nFileLength); 5\quh2Q_
// fileSplitterFetch[nPos.length-1].start(); HU?1>}4L
uZn_*_J!
S,:!H@~B
//等待子线程结束 EX{%CPp7}
//int count = 0; /P,1KVQPh
//是否结束while循环 ]j7`3%4uK
boolean breakWhile = false; p+=zl`\=|
F(`|-E"E;
i_*yS+Z;
while(!bStop) fU$Jh/#":
{ -M=BD-_.h
write_nPos(); @~hy'6/
Utility.sleep(500); $jh$nMx)!
breakWhile = true; 85&7WAco"B
tP|/Q5s
$5G(_
for(int i=0;i<nStartPos.length;i++) "7%jv[
{ O"~[njwkE
if(!fileSplitterFetch.bDownOver) s&nat4{B
{ L3I$ K+c
breakWhile = false; ||X3g"2W9
break; OlyW/hd
} HQ"T>xb
} 0a:oC(Ak
if(breakWhile) B;[ .u>f
break; n! 5(Z5=
n[DRX5OxR'
afX|R
//count++; eowwN>-2C
//if(count>4) Ich^*z(F$
// siteStop(); iqB5h| `
} ~vDa2D<9%
*D%w r'!>
9cB+x`+Lu
System.err.println("文件下载结束！"); 0^>,
} !%65YTxY-
catch(Exception e){e.printStackTrace ();} npzp/mcIe)
} k^ZP~.G
(mP{A(kwJ
ep"{{S5g
//获得文件长度 rVP\F{Q4Tr
public long getFileSize() '8)kFR^9
{ AcuZ?LYzK
int nFileLength = -1; F&!vtlV)
try{ 4#>Z.sf
URL url = new URL(siteInfoBean.getSSiteURL()); [(Z(8{3i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f$:Y'$Z1
httpConnection.setRequestProperty("User-Agent","NetFox"); Zfk]Z9YO
G8vDy1`q6
I\_2=mL
int responseCode=httpConnection.getResponseCode(); /v9qrZ$$
if(responseCode>=400) RdD>&D$I
{ bj@sci(1?
processErrorCode(responseCode); RN 4?]8
return -2; //-2 represent access is error f@YdL6&d-
} U)f('zD
nxhlTf>3
z<9C-
String sHeader; !dwZ`D
s i2@k
kP$E+L
for(int i=1;;i++) $=diG
{ pnSKIn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KE"6I
//Utility.log(in.readLine()); :z P:4NW
sHeader=httpConnection.getHeaderFieldKey(i); c6 &k?Puy
if(sHeader!=null) nZnqXclzxn
{ KwHN c\\
if(sHeader.equals("Content-Length")) (U#,;
{ pW.WJ`Rk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >?K=l]!(*
break; mvH8hvD9
} uQc("F
} glCpA$;VPu
else ?7wcv$K5
break; !HU$V9C
} '8zd]U
} er24}G8
catch(IOException e){e.printStackTrace ();} oS$7k3s fj
catch(Exception e){e.printStackTrace ();} *#>(P
'z,kxra|n
MzUKp"
Utility.log(nFileLength); ^@8XJ[C,_
bP-(N14x+
;UgwV/d
return nFileLength; V0{#q/q
} Q e+;BE-H
7/a7p(
8D`+3
//保存下载信息（文件指针位置） ,w6?Ap
private void write_nPos() i/-IjgM"-
{ :'%|LBc0
try{ j;uUM6
output = new DataOutputStream(new FileOutputStream(tmpFile)); {sB-"NR`K
output.writeInt(nStartPos.length); nI?*[y}
for(int i=0;i<nStartPos.length;i++) ][l5S*CC_
{ \y?*} L
// output.writeLong(nPos); Xh}q/H<
output.writeLong(fileSplitterFetch.nStartPos); *JX$5bZsI
output.writeLong(fileSplitterFetch.nEndPos); SujEF`"
} SaGI4O_\s
output.close(); pD[&,gV$
} @bTm.3
catch(IOException e){e.printStackTrace ();} [sG`D-\P[
catch(Exception e){e.printStackTrace ();} {J1rjrPo
} KB~1]cYMp
<-N eusx%
[dLc+h1{B
//读取保存的下载信息（文件指针位置） yn ofDGAf
private void read_nPos() 6{i0i9Tb
{ MHWc~@R
try{ yxx_%9X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >CKa?N;
int nCount = input.readInt(); !lzj.|7=1
nStartPos = new long[nCount]; %P1zb7:8
nEndPos = new long[nCount]; {BM:c$3@j
for(int i=0;i<nStartPos.length;i++) :|k!hG
{ b/\O;o}]
nStartPos = input.readLong(); 4J,6cOuW4
nEndPos = input.readLong(); ?z M
} VJK4C8]
input.close(); jo"+_)]
} *{5}m(5F
catch(IOException e){e.printStackTrace ();} 7ojh=imY
catch(Exception e){e.printStackTrace ();} RgFpc*.T
} o"RE4s\G~r
anz7ae&P'K
4`v[p4k
private void processErrorCode(int nErrorCode) Ap\]v2G
{ b*|?7
System.err.println("Error Code : " + nErrorCode); Vt zSM%=
} moVf(7
lbIW1z%:sy
GPAC0K^p
//停止文件下载 YVRE9
public void siteStop() FLPN#1
{ oIE(`l0l
bStop = true; .-s!} P"
for(int i=0;i<nStartPos.length;i++) aAoAjVNkK
fileSplitterFetch.splitterStop(); |'i ?o
Zq1> M'V;
UlN}SddI9
} b,HXD~=
} 7je1vNs
//负责部分文件的抓取 @AG=Eq9<o
**FileSplitterFetch.java D//58z&
*/ xop\W4s_
package NetFox; )}w-;HX
35-FD{
Jz;`L3m
import java.io.*; %iV\nFal>
import java.net.*; ~U?vB((j!
E.VEW;=
NFIFCy!
public class FileSplitterFetch extends Thread { Z-U3TrSI
@J@bD+Q+0
I GcR5/3
String sURL; //File URL YRl4?}r2
long nStartPos; //File Snippet Start Position P#A|Pn<p
long nEndPos; //File Snippet End Position NVC$8imip
int nThreadID; //Thread's ID Yic'p0< ?V
boolean bDownOver = false; //Downing is over CA"`7<,
boolean bStop = false; //Stop identical 0XIrEwm@%
FileAccessI fileAccessI = null; //File Access interface y7*^H
DUm/0q&
Ke&fTK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >W8PLo+i
{ 6d 8n1_
this.sURL = sURL; !q PUQ+
this.nStartPos = nStart; v#IZSBvuQK
this.nEndPos = nEnd; YX2j;Y?
nThreadID = id; VxAR,a1+n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z#&qWO
} uoBPi[nK
h"nv[0!)
pm;g)p?
public void run() :(x 90;DW
{ X_|} b[b
while(nStartPos < nEndPos && !bStop) ]zK} X!
{ lu.2ZQE
PsD]gN5"
C[$<7Mi|;
try{ &jPsdv h
URL url = new URL(sURL); %nc+VL4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~yf5$~Z
httpConnection.setRequestProperty("User-Agent","NetFox"); 7~`6~qg.
String sProperty = "bytes="+nStartPos+"-"; `Op ";E88
httpConnection.setRequestProperty("RANGE",sProperty); ')FNudsC
Utility.log(sProperty); @49^WY
E3KPJ`=!*"
bmddh2
InputStream input = httpConnection.getInputStream(); aH$*Ue@Q
//logResponseHead(httpConnection); RMrt4:-DI
D{z=)'/F
\S2'3SDd/
byte[] b = new byte[1024]; cRfX
int nRead; h/w- &7t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uc"u@ _M
{ KJkcmF}Q
nStartPos += fileAccessI.write(b,0,nRead); 3i$AR
//if(nThreadID == 1) ta4<d)nB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YvHn~gNPhs
} kI;^V
?x/L"h&Kp
^e 6(#SqR
Utility.log("Thread " + nThreadID + " is over!"); E|Lh$9XONA
bDownOver = true; 5Np.&
//nPos = fileAccessI.write (b,0,nRead); LtvyWc`
} [E/3&3
catch(Exception e){e.printStackTrace ();} wb9zJAsc
} gR>#LM&dG
} tE>:kx0*3
~gDtj&F
tr}$82Po
//打印回应的头信息 #sHP\|rA
public void logResponseHead(HttpURLConnection con) ^b.J z}
{ 3G&1. 8
for(int i=1;;i++) /kq~*s
{ x[kdQj2[&
String header=con.getHeaderFieldKey(i); Zn!SHj
if(header!=null) cK } Qu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {gn[ &\
Utility.log(header+" : "+con.getHeaderField(header)); P$QfcJq&c*
else 33C#iR1(WJ
break; &pAT
} 8|/YxF<
} J{ Vl2P?@
32Z4&~I
(TQXG^n$gY
public void splitterStop() YD%Kd&es
{ RPWYm
bStop = true; \3/9lE|gh
} v]!7=>/2
IR&u55#I6
*%e#)sn*
} rG]Xgq"
~eP2PG
l]Sui_+ZU
/* ^pP 14y*go
**FileAccess.java 2S4z$(x3
*//文件访问(定位，写) fYi!Z/Ck2
package NetFox; VGq]id{*$
import java.io.*; )Fw)&5B!
#wyS?FP-
'9gI=/29D
public class FileAccessI implements Serializable{ >A/=eW/q
Fqv5WoYVf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BTyVfq sx
RandomAccessFile oSavedFile; jo*9QO
long nPos; DPOPRi~
:Mk}Suf&H
u/f&Wq/
public FileAccessI() throws IOException /WfxI>v
{ :6+~"7T
this("",0); c"ztrKQQ
} %U7B0-
Mm!saKT%
0Pk-FSY|f
public FileAccessI(String sName,long nPos) throws IOException %-Z~f~<?
{ cw.7YiU
oSavedFile = new RandomAccessFile(sName,"rw"); cIp h$@
this.nPos = nPos; Fe.*O`
oSavedFile.seek(nPos); A2d2V**Z
} v3Yj2LSqx
3D0I5LF&
&?6w2[}
public synchronized int write(byte[] b,int nStart,int nLen) vNbA/sM
{ cG:`Zj~4
int n = -1; HV.7IyBA^
try{ \irjIXtV
oSavedFile.write(b,nStart,nLen); dk/*%a +
n = nLen; o=QF>\\
} G65N:
catch(IOException e) ZZ*k3Ce
{ w ZAXfNA
e.printStackTrace (); :\_MA^<
} ~*Qpv&y)
(qN(#~
Rn_c9p
return n; ?y)X$D^
} KCE-6T
V?BVk8D};
V bOLTc
} &NeYKh?
j:3Hm0W3
^6>|!
/* ycD.:w p\'
**SiteInfoBean.java -<]_:Kf{;&
*/ wlg#c6#q
package NetFox; ? M_SNv
mtddLd,
/ASI0h
public class SiteInfoBean { lG>e6[Wc
]_8I_VcQ
`|Z@UPHzG
private String sSiteURL; //Site's URL %W;Gf9.w
private String sFilePath; //Saved File's Path \|`Pul$
private String sFileName; //Saved File's Name Tk&9Klo
private int nSplitter; //Count of Splited Downloading File ya g
C)p<M H<
h##?~!xDmq
public SiteInfoBean() BrMp_M
{//nSplitter的缺省值为5 _)2TLA n3
//default value of nSplitter is 5 3MJWCo-[
this("","","",5); |o=ST
} <|Eby!KXR
eAKQR
14!a)Ijl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f?zK"
{ DeQ'U!?+N
sSiteURL= sURL; .t[ZXrd|0
sFilePath = sPath; KVpAV$|e
sFileName = sName; 0lr4d Y
this.nSplitter = nSpiltter; K |} ]<
qZ_fQ@
?mfWm{QTt
} 7C7(bg,7^
^^3va)1{!
!_H8Q}a
public String getSSiteURL() tSc>@Q_|
{ A6y~_dt
return sSiteURL; exEld
} G|oB'~{&
qs1.@l("
hIo S#]
public void setSSiteURL(String value) ~K$"PKs3
{ 7a]Zws
sSiteURL = value; ) wo2GF
} $]U5
uQtk|)T E
)P9{47
public String getSFilePath() Dw/Gha/
{ s]<r
return sFilePath; lJ]\
} ?"<r9S|[O
-1r&s
""v`0OP&J
public void setSFilePath(String value) H0b6ZA%n
{ vV\F^
sFilePath = value; R{xyme@"^
} $X=D9h
LXu"rfp
<AAZ8#^
public String getSFileName() kl3S~gE4@
{ IL[|CB1v
return sFileName; _QMHPRELk
} 90h1e7ZcC
&kjwIg{
|RAQ%VXm
public void setSFileName(String value) Wt)SdF=U/
{ ,[}yf#8@J
sFileName = value; bu"68A;>
} t3#H@0<
T^%n!t
m!#)JFe67
public int getNSplitter() {Sr=SE
{ KIAe36.~
return nSplitter; +/!=Ub[:U
} ? __aVQ7
[#>$k 6F*
N{hF [F
public void setNSplitter(int nCount) IzGB
{ <jRFN&"h}
nSplitter = nCount; Zu0;/_rN
} #[U9(44,
} lA.;ZD!
-wfRR>)d
%7(kP}y*
/* InPy:}
**Utility.java VTJIaqw
*/ aZawBU.:
package NetFox; NO+ 55n
8R)D! 7[l
sR>`QIi(a
public class Utility { 0Y6q$h>4
( *9Ip
Q9yGQu
public Utility() hSkc9jBF
{ I NPYJ#%
Pn+IJ=0Y
V{T{0b"\U
} CCW%G,$U9
UKKSc>D1
//线程睡眠 YH'$_,8peM
public static void sleep(int nSecond) ?y>Y$-v/C
{ up3?$hUc.
try{ l- 1]w$ y
Thread.sleep(nSecond); {ywXz|TP
} M q^|M~
catch(Exception e) ^zaKO'KcV
{ 2<[eD`u
e.printStackTrace (); XdGpW
} QM[A;WBr7
} mfeMmKFu\
CYPazOfj
//日志 " K 8&{=
public static void log(String sMsg) KMK&[E#r
{ 4?>18%7&
System.err.println(sMsg); k'[ S@+5
} 49+ >f
;m@1Ec@*p
J+)'-OFt0
public static void log(int sMsg) kgbobolA
{ &jV9*
System.err.println(sMsg); ex` xkZ+
} 0W T#6D
} :vc[/<
vix&E`0yD
dSOlD/c
/* 3[0w+{(Q
**TestMethod.java ;YK!EMM4!h
*/ xab]q$n]k
package NetFox; NXzU0
2[Z0I4r
cS<TmS!
public class TestMethod { I86e&"40
t6'61*)|0
?mH@`c,fM
public TestMethod() jW-;4e*H=V
{ ///xx/weblogic60b2_win.exe cQ8dc+ {
try{ p=!#],[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #*!+b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `IEq@Wr#$!
SiteFileFetch fileFetch = new SiteFileFetch(bean); kWB, ;7
fileFetch.start(); \\=.6cg<K
} `1nRcY
catch(Exception e){e.printStackTrace ();} f>.4-a?
Tr}R`6d$
ZlthYuJ
} B|cA[
wA?@v|,dZ
X?tj$
public static void main(String[] args) \r)%R5_CQ
{ tf4*R_6;1$
new TestMethod(); Y4QLs^IdB
} 2 9q?$V(
} as>:\hjP##
点击下载更多相关资料