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)); sV"UI
} Q_-_^J
for(int i=0;i<nEndPos.length-1;i++) _|[UI.a
{ y$FW$Ka
nEndPos = nStartPos[i+1]; ajR%c2G;
} 2WX7nK;I
nEndPos[nEndPos.length-1] = nFileLength; J]lrS
} nRL. ppUI
} x+ncc_2n&D
M5nWVK7c
B~]5$-
//启动子线程 Qd}m`YW-f$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7w,FX.=;cv
for(int i=0;i<nStartPos.length;i++) DI+]D~N
{ d@`M CchCB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), voP7"Dl[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wN1niR'
nStartPos,nEndPos,i); |8>3`w!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dI&!e#Y
fileSplitterFetch.start(); j`^$#
} $vC1 K5sLk
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QO;N9ZI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zJP6F.Ov!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X[`bMa7IB(
nEndPos = " + nFileLength); b2aF 'y/
// fileSplitterFetch[nPos.length-1].start(); EVp,Q"V]
`>0MNmu
B`*ZsS=R-
//等待子线程结束 p&+;w
//int count = 0; 5^']+5_vb
//是否结束while循环 fVb-$
boolean breakWhile = false; eSWLrryY
(py]LBZ
w0w G-R ?
while(!bStop) +fvaUV_-
{ FZ!`B]]le,
write_nPos(); H 0+dV3
Utility.sleep(500); \fA{1
breakWhile = true; bM8If"
7VcmVq}X
=mA: ctu~v
for(int i=0;i<nStartPos.length;i++) S*j6OwZ
{ IDnC<MO>
if(!fileSplitterFetch.bDownOver) 'smWLz}
{ /}Jj
breakWhile = false; ono4U.C9
break; 3a.kBzus
} :Y9NLbv
} 'F>'(XWWQ
if(breakWhile) zSo)k~&[3
break; Q+4Xs.#
kOIt(e
_g1b{$
//count++; 6-?66gmT
//if(count>4) K>*a*[t0Sy
// siteStop(); V&-~x^JK
} J7r|atSk
fS~;>n%R
/rUo{j
System.err.println("文件下载结束！"); PaV-F_2
} ,-7R(iMd
catch(Exception e){e.printStackTrace ();} =-_B:d;
} m(pE5B(
EwOV;>@T?
7S?4XyU/o
//获得文件长度 \[Z?&
public long getFileSize() `rf_7
{ +$oF]OO
int nFileLength = -1; @V03a )6,h
try{ Eb=}FuV
URL url = new URL(siteInfoBean.getSSiteURL()); XC.%za8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @|Rrf*J?%
httpConnection.setRequestProperty("User-Agent","NetFox"); \Y"Wu
2WU@*%sk"
/yM:|`tT
int responseCode=httpConnection.getResponseCode(); m1Y>Nj[f
if(responseCode>=400) ~gGZmTb
{ 4:U?u
processErrorCode(responseCode); _i/t?7
return -2; //-2 represent access is error _YF%V;X
} 6/rFHY2q
9K9DF1SOa
=i~}84>
String sHeader; a'z)
+nJUFc
:=J,z,H_U
for(int i=1;;i++) =$]uoA
{ d/i`l*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &197P7&o
//Utility.log(in.readLine()); =}.EY iD
sHeader=httpConnection.getHeaderFieldKey(i); m9/}~Y#k
if(sHeader!=null) m=YU2!Mb
{ qK)73eNSR
if(sHeader.equals("Content-Length")) 66fO7OJs
{ ~8lwe*lNV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r/SG 4
break; D9z|VIw8
} r#XT3qp$d
} 9uGrk^<t
else qAw x2fPu
break; fFc/ d(
} wXsmn1w9
} ~R(%D-k
catch(IOException e){e.printStackTrace ();} LqA@&H
catch(Exception e){e.printStackTrace ();} eut-U/3:#
l5"OIq
V O3x~E
Utility.log(nFileLength); 8QM(?A
q5?# 3T=
JU4qzi
return nFileLength; t+eVR8
} l8?>>.<P=
2$Tj84'X
%Ah^E$&n2
//保存下载信息（文件指针位置） y3h/IpT
private void write_nPos() V3"=w&2]K
{ 5=f|7yl
try{ ELj\[&U
output = new DataOutputStream(new FileOutputStream(tmpFile)); z_|/5$T>U
output.writeInt(nStartPos.length); ,lyb!k8
for(int i=0;i<nStartPos.length;i++) }`@728E
{ lyGhdgWc
// output.writeLong(nPos); JYTP 2
output.writeLong(fileSplitterFetch.nStartPos); ,G2TVjz
output.writeLong(fileSplitterFetch.nEndPos); 2sJ(awN>
} 92 [;Y
output.close(); 0zi~p>*nJC
} $C `;fA
catch(IOException e){e.printStackTrace ();} >(;{C<6|^
catch(Exception e){e.printStackTrace ();} /oriW;OF
} ;72T|e
~-I+9F
%HL*c=
//读取保存的下载信息（文件指针位置） ll C#1
private void read_nPos() nVi[
{ jrS[f
try{ 1&- </G#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )'~6HO8Z
int nCount = input.readInt(); ={z*akn,
nStartPos = new long[nCount]; RRI"d~~F6
nEndPos = new long[nCount]; {HCzp,Y
for(int i=0;i<nStartPos.length;i++) a]MX)?
{ ?#45wC
nStartPos = input.readLong(); 7Zh~lM
nEndPos = input.readLong(); |>#{[wko
} f\jLqZY
input.close(); G%s2P.cd
} Iu <?&9t
catch(IOException e){e.printStackTrace ();} mVy|{Oh
catch(Exception e){e.printStackTrace ();} ]bK=FIK2
} QnJZr:4b
2K3{hxB
8p:j&F
private void processErrorCode(int nErrorCode) D ^x-^6^
{ w/kt3Lw
System.err.println("Error Code : " + nErrorCode); ](s'L8(x
} 6*3.SGUY
RS^lKJ1 U
q,+yqrt
//停止文件下载 eN^qG 42
public void siteStop() M#8uv-L
{ ;S>])5<
bStop = true; (Kv#m 3~
for(int i=0;i<nStartPos.length;i++) [xGf,;Z
fileSplitterFetch.splitterStop(); 7eiV{tYF
%;rHrDP(>
Wh.?j>vB
} |b)Y#)C;
} tfGHea)M
//负责部分文件的抓取 !s&NT @ S
**FileSplitterFetch.java <UQe.K"
*/ !Y[lQXv
package NetFox; XR;eY:89
N9v1[~ bv_
]VD|xm:kj
import java.io.*; [_}J F}6
import java.net.*; W#hj 1
=,UWX3`f
Y$?9Zkp>
public class FileSplitterFetch extends Thread { LL3#5AA"k|
"*Tb" 'O
vuoQz\
String sURL; //File URL hBBUw0"
long nStartPos; //File Snippet Start Position 6,0_)O}\b
long nEndPos; //File Snippet End Position 5Er2}KZJv,
int nThreadID; //Thread's ID L{8xlx`
boolean bDownOver = false; //Downing is over E6pMT^{K
boolean bStop = false; //Stop identical 9T*v9d
FileAccessI fileAccessI = null; //File Access interface DKBSFm{~Q
<=>=.kmGt
s;6CExH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException * /:x sI
{ lp(8E6
this.sURL = sURL; }Nf%n@
this.nStartPos = nStart; H{=21\a\
this.nEndPos = nEnd; uLWh|
nThreadID = id; E(Z8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mD^jd+
} D?NbW @]
#6CC3TJ'k
[D<1CF
public void run() C,NJb+J
{ BS:+~|3w
while(nStartPos < nEndPos && !bStop) 7eV di*
{ ;e1ku|>$
U 15H2-`
<|SRe6m
try{ ;{U@qQD7
URL url = new URL(sURL); ]3X@_NYj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oyYR-4m\
httpConnection.setRequestProperty("User-Agent","NetFox"); ~2gG(1%At9
String sProperty = "bytes="+nStartPos+"-"; %3ICI
httpConnection.setRequestProperty("RANGE",sProperty); 1f":HnLRM
Utility.log(sProperty); ]hFW73FV
}#&#^ B#?O
HBu[gh;b
InputStream input = httpConnection.getInputStream(); ''0fF_P
//logResponseHead(httpConnection); W7 #9jo
w tiny,6
i:OK8Q{VI
byte[] b = new byte[1024]; 6jC`8l:
int nRead; Bg|5KOnd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Aj+2;]M
{ Y07ZB'K
nStartPos += fileAccessI.write(b,0,nRead); '.81zpff
//if(nThreadID == 1) SAyufLEv,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @T'i/}nl
} kNobl
_s .G
*%S"eWb
Utility.log("Thread " + nThreadID + " is over!"); -)RH5WGS
bDownOver = true; jAm3HI
//nPos = fileAccessI.write (b,0,nRead); MMx9(`t*.
} PqiB\~o@Z
catch(Exception e){e.printStackTrace ();} T^Ze3L]
} 9Ru8~R/\
} N<IT w/@^
$Z\.-QE\
FXi{87F2
//打印回应的头信息 Jc|6&
public void logResponseHead(HttpURLConnection con) ]]oI#*c
{ VCD:3U 8
for(int i=1;;i++) 8j=}u/T@F
{ x6e}( &p*
String header=con.getHeaderFieldKey(i); tX> G,hw
if(header!=null) |4uWh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )C(?bR
Utility.log(header+" : "+con.getHeaderField(header)); &I (#Wy3
else hNH'XQxO
break; YTexv;VNb|
} \l]DQaOEe
} tavpq.0O
Cc%LztP>
rU2%dkTa
public void splitterStop() K"4>DaK2P
{ Zf65`K3
bStop = true; D0%Ug>
} (K)]qNH
Te<}*qvD
L>SjllY
} :n.f_v}6
j]aoR
dAkgR~
/* @jsDq Ln
**FileAccess.java enSXP~9w
*//文件访问(定位，写) Z(ACc9k6:'
package NetFox; bqnNLs<N
import java.io.*; C ihAU"
/p+>NZ"b
@!yMIM%P
public class FileAccessI implements Serializable{ s3R(vd
%sX$nmi3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =p=rg$?
RandomAccessFile oSavedFile; d\ 1Og\U|A
long nPos; qT`k*i?
%Ntcvp)
N#DYJ-~*
public FileAccessI() throws IOException &' Ne!o8
{ b;cdIl!3
this("",0); C0}IE,]
} bdF.qO9
/$'AjIg4:&
3~S8!nx
public FileAccessI(String sName,long nPos) throws IOException :QB<?HaS'
{ 9&` 2V
oSavedFile = new RandomAccessFile(sName,"rw"); b/{t|io{
this.nPos = nPos; .tzG_
oSavedFile.seek(nPos); :]^P1sH[
} NT+?#0I
QUQu^p
~XWQhIAM4
public synchronized int write(byte[] b,int nStart,int nLen) lJis~JLd`
{ ;[u%_
int n = -1; ] 0B2# d
try{ jkt_5+S
oSavedFile.write(b,nStart,nLen); 2L} SJUk*
n = nLen; g#t[LI9(F[
} }7 c[Q($K
catch(IOException e) -U/c\-~fU
{ tjluk
e.printStackTrace (); +(1zH-^.
} )XzI #iQ
<\}KT*Xp
HP3lz,d
return n; zN"J}r:
} Y#lk6
7U2J xE
=yyp?WmC8
} Bb}fj28
viMzR(JU
HFaj-~b
/* T2!6(, s9
**SiteInfoBean.java K3x.RQQ-
*/ 7|[mz> "d
package NetFox; vDxe/x%
yX0dbW~@y
8W#heW\-]
public class SiteInfoBean { .sj^{kGE
d BJJZ^(
zOa_X~!@
private String sSiteURL; //Site's URL V*iH}Y?^p
private String sFilePath; //Saved File's Path LG1r]2
private String sFileName; //Saved File's Name )Hk3A$6(
private int nSplitter; //Count of Splited Downloading File eK!V );
IuRmEL_Q_
[ zEUH:9D
public SiteInfoBean() )_i qAqkS
{//nSplitter的缺省值为5 vbD{N3p)?n
//default value of nSplitter is 5 4y'OMRy
this("","","",5); Wv/%^3
} (m:Zk$
qycI(5S,
q~vDz]\G
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nC}6B).el
{ CS=qj-(
sSiteURL= sURL; }=8B*
sFilePath = sPath; *]VFvh
sFileName = sName; bdibaN-h
this.nSplitter = nSpiltter; CCWg{*og
`/ q|@B7
T<w5vqFDu
} qASqscO
uec!RKE
|Clut~G
public String getSSiteURL() 'Ub g0"F(
{ HsHB!mQV
return sSiteURL; \&iP`v`K
} D0#x Lh
B&.FOO
u(wGl_
public void setSSiteURL(String value) 846$x$G4
{ y?a Acn$
sSiteURL = value; 3rcKzS7
} X90J!
.D:Z{|.1
d)R:9M}v
public String getSFilePath() KB'qRnkc
{ sPMa]F(
return sFilePath; P3nb2.
} N.]qU d
8qu2iPOcZ
IS#FiH
public void setSFilePath(String value) zOqn<Y@
{ !>e5z|1
sFilePath = value; 'F_8j;
} X(\fN[;
~YRDyQ:%T
Mc%Nf$XQ
public String getSFileName() aP8H`^DFX>
{ pSr{>;bN
return sFileName; l#H#+*F
} ]) rrG/3
'iGzkf}j
$;/}?QY(
public void setSFileName(String value) MV\|e1B}
{ W'.s\e?gh
sFileName = value; 2#<xAR
} %d>=+Ds[
k-HCeZ
:)_~w4&
public int getNSplitter() _:-ha?W$;y
{ LX@/RAd vz
return nSplitter; L2pp6bW
} )d$glI+
kWe{r5C7
C_n9T{k
public void setNSplitter(int nCount) 2;^y4ssg
{ zSSB>D
nSplitter = nCount; @*Wh
} .Y3pS/VI
} z(fAnn T?
ae*Mf7
z[cyA.
/* HKqwE=NZ
**Utility.java ld^=#]g
*/ q*7zx_ o
package NetFox; rSHpS`\ou
eXKo.JL
B|4X}*@SX
public class Utility { )~+e`q
tvu!< dxZ
F^5?\
public Utility() sp5eVAd
{ NLrPSqz
OnF3lCmu
pDh{Z g6t
} -|Y(V5]
BVr0Gk
//线程睡眠 GW$.lo1|)
public static void sleep(int nSecond) &g.+V/<[
{ L. EiO({W
try{ =9z[[dQ|L
Thread.sleep(nSecond); e#Z$o($t
} Yb/i{@AJ
catch(Exception e) tX@_fYb
{ 59%tXiO
e.printStackTrace (); wmTq` XH)
} AwTJJ0>
} "v`
Z7_ zMM
//日志 ~5 *5
public static void log(String sMsg) 3q'&j,,^
{ 2A\,-*pc
System.err.println(sMsg); W ]Nv33i [
} .h& .K
1XnZy5fEo
baP^<w^
public static void log(int sMsg) +Wx{:
{ w^#L9i'v'
System.err.println(sMsg); fuA&7gNC
} "7v@Rye
} 2con[!U
E6,4RuCK
ObE,$_ k
/* ;+tpvnV;]
**TestMethod.java ~,BIf+\XF
*/ :sP!p`dl
package NetFox; /-qxS <?o
:LQ5u[g$\
K,e w>U
public class TestMethod { x#Q>J"g
7yx$Nn`(
>A<bBK#
public TestMethod() _^'I
{ ///xx/weblogic60b2_win.exe V`RNM%Y
try{ i@B[ eta
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [ e8x&{L-_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <TE%Prd}`
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9{$<0,?
fileFetch.start(); *0}3t<5
} ^kgBa27
catch(Exception e){e.printStackTrace ();} .-IkL|M
8?i7U<CB
(&P9+Tl
} vi|R(&
kdCP
v9D22,K-
public static void main(String[] args) x&`~R>5/
{ 0k'e:AjP
new TestMethod(); Ezi-VGjr]
} IZm(`b;t^
} ^m/oDB-
点击下载更多相关资料