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)); l?_h(Cq<
} V !Cu%4
for(int i=0;i<nEndPos.length-1;i++) ;=&D_jGf]
{ dr25;L? B
nEndPos = nStartPos[i+1]; \t'v-x>2y5
} 3 #fOrNU2
nEndPos[nEndPos.length-1] = nFileLength; H|E{n/g
} t#kPEiD
} d+ LEi^
uxbDRlOS
3' HtT
//启动子线程 t}Z*2=DO
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2>Uy`B|f
for(int i=0;i<nStartPos.length;i++) WYHr'xJ
{ q\PHA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MhE'_sq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3YtFO;-
nStartPos,nEndPos,i); %?o@YwBo^E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cfb8kNn~+
fileSplitterFetch.start(); =1rq?M eX
} aJnZco6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (9;qV:0`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r_sZw@lqJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?J;*
nEndPos = " + nFileLength); w(lxq:>"
// fileSplitterFetch[nPos.length-1].start(); /0w?"2-
W*'gqwM&
,zCrix 3
//等待子线程结束 wm3fd7T
//int count = 0; /eM_:H5
//是否结束while循环 \\j98(i
boolean breakWhile = false; M6ol/.G[
]Q}z-U
Dxc`K?M
while(!bStop) \O]1QM94Y
{ G4!$48
write_nPos(); =~Ac=j!q
Utility.sleep(500); $N7:;X"l
breakWhile = true; >E;&SX
S#M<d~rK
vt;<+"eps
for(int i=0;i<nStartPos.length;i++) 0:W*_w0Ge
{ kNX(@f
if(!fileSplitterFetch.bDownOver) :#M(,S"Qq
{ G\ twx ;
breakWhile = false; %cM2;a=2
break; X@,xwsM%tb
} SE0"25\_G
} '/gw`MJ
if(breakWhile) #y~`nyg%|
break; jni }om
:!vDX2o)\
sLx!Do$'
//count++; %4Nq T
//if(count>4) RvL-SI%E
// siteStop(); dAOmqu,6
} bSW!2#~
8G?{S.%.
u~X]W3
System.err.println("文件下载结束！"); >x%Z^U
} 7)S;VG k
catch(Exception e){e.printStackTrace ();} U=<E,tM
} MC5M><5\
k~ZwHx(%S
e+"rL]
//获得文件长度 Dk#$PjcRE
public long getFileSize() Jo1=C.V`Y
{ \ H#zRSbZ
int nFileLength = -1; }r&^*" 2=
try{ A9lnQCsJ
URL url = new URL(siteInfoBean.getSSiteURL()); Sd]`I)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xUYUOyV
httpConnection.setRequestProperty("User-Agent","NetFox"); 1>W|vOv"Z?
6&% c
*Z7W'-
int responseCode=httpConnection.getResponseCode(); CtbmX)vE
if(responseCode>=400) F+vgkqs@9
{ 5S'89 r3m
processErrorCode(responseCode); ~ifo7,
return -2; //-2 represent access is error ?i*kwEj=
} ~4th;#'
Q!Rknj 2
Pms"YhyZ7
String sHeader; E Kks8
Mn(:qQo^&`
'xAfcP[^
for(int i=1;;i++) A{Giz&p
{ tP2hU[7Z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #RoGyrLo
//Utility.log(in.readLine()); ~={8b
sHeader=httpConnection.getHeaderFieldKey(i); Oy$*ZG)
if(sHeader!=null) e:IUO1#
{ M{+Ie?ZI
if(sHeader.equals("Content-Length")) H kDT14 `&
{ #SQao;>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rmc0dm&l]
break; bH+p5Fd;
} nG&=$7x^
} RE`XyS0Q
else [QA@XBy6
break; #KZ6S9>@
} '7Dg+a^x7
} 7g3vh%G.
catch(IOException e){e.printStackTrace ();} I&|%Fn
catch(Exception e){e.printStackTrace ();} A?8f 6
Oqeoh<y!\
Ia:n<sZU
Utility.log(nFileLength); V%?oI]" l
TFWV(<
n= yT%V.l
return nFileLength; qsXK4`
} {ScilT
tG(?PmQ
z cN1i^
//保存下载信息（文件指针位置） EY;C5P4
private void write_nPos() a6"Pe07t
{ |Vc8W0~0
try{ L%9DaK
output = new DataOutputStream(new FileOutputStream(tmpFile)); DLe?@R5
output.writeInt(nStartPos.length); jx a?
for(int i=0;i<nStartPos.length;i++) 'E+Ty(ED5
{ j?4k{?x
// output.writeLong(nPos); W!4(EdT*Cq
output.writeLong(fileSplitterFetch.nStartPos); ; k{w@L.@
output.writeLong(fileSplitterFetch.nEndPos); .r+u pY
} !'(bwbd
output.close(); a5C%OI<
} J3cbDE%^m
catch(IOException e){e.printStackTrace ();} P4"_qxAW
catch(Exception e){e.printStackTrace ();} *[@lp7
} a+ZP]3@ 7
?UnOi1"v9
i]gF 6:&
//读取保存的下载信息（文件指针位置） L=ZKY
private void read_nPos() ~{'.9
{ 4FEOV,n
try{ cf?*6q?n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;1^_.3
int nCount = input.readInt(); eZR{M\Q
nStartPos = new long[nCount]; w+gA3Dg
nEndPos = new long[nCount]; Y s[JxP
for(int i=0;i<nStartPos.length;i++) sG*1?
{ |=2E?&%?
nStartPos = input.readLong(); >t')ZSjRs
nEndPos = input.readLong(); :<f7;.
} #rM/
input.close(); hu.c&Q>
} p< Emy%
catch(IOException e){e.printStackTrace ();} v??}d
catch(Exception e){e.printStackTrace ();} 7k}[x|u
} -S\74hA
Z?|\0GR+`5
rr>*_67-:
private void processErrorCode(int nErrorCode) 1a4 [w
{ 2[: *0 DV#
System.err.println("Error Code : " + nErrorCode); / 2>\Z(
} znv2:
IM),cOp=
)?RR1P-ID
//停止文件下载 o,(MB[|hQ
public void siteStop() WgPpW!`
{ K4NB#
bStop = true; #FKo:id`K
for(int i=0;i<nStartPos.length;i++) o^%4w>|
fileSplitterFetch.splitterStop(); Q.Uyl:^PxU
0\#uxzdhJ
DZKVZ_q
} i&\N_PUm[
} 5fuOl-M0W
//负责部分文件的抓取 DJP)V8]!B
**FileSplitterFetch.java ~.7r
*/ Y}%=:Yt
package NetFox; Q`}1 B
52K_kB5
+[M5x[[$
import java.io.*; .w2X24Mmb
import java.net.*; _!6~o>
OnFx8r:q@%
AHX_I
public class FileSplitterFetch extends Thread { 4HEp}Y"}V
vk:@rOpl
rCqcl
String sURL; //File URL M0g!"0?
long nStartPos; //File Snippet Start Position ~E&drl\
long nEndPos; //File Snippet End Position Wo&10S w
int nThreadID; //Thread's ID f@&C \
boolean bDownOver = false; //Downing is over '^"6EF.R
boolean bStop = false; //Stop identical 3D70`u
FileAccessI fileAccessI = null; //File Access interface afOb-G$d=
v+dt1;
_UKH1qUd4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1~NXCIdF
{ WzYy<
this.sURL = sURL; 1V(tt{
this.nStartPos = nStart; z 3)pvX5
this.nEndPos = nEnd; {FyGh */
nThreadID = id; :c%vl$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <Okk;rj2
} m@ b~
_=@9XvNM
!/O c)Yk
public void run() Q| > \{M
{ c-8Pc]+g
while(nStartPos < nEndPos && !bStop) {<%zcNKl^L
{ ;B>2oq
#|`/K[.xd%
7RNf)nz
try{ wQiRj.
URL url = new URL(sURL); "Wd?U[[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M?pu7wa
httpConnection.setRequestProperty("User-Agent","NetFox"); j&)"a,f
String sProperty = "bytes="+nStartPos+"-"; Un\h[m
httpConnection.setRequestProperty("RANGE",sProperty); 4hwUH
Utility.log(sProperty); vy\;#X!
Uv'.]#H<
~yz7/?A)TS
InputStream input = httpConnection.getInputStream(); u(V4KUk
//logResponseHead(httpConnection); is_`UDaB
+`g&J
3#vhQ*xU
byte[] b = new byte[1024]; $$+6=r}
int nRead; ;,GE!9HW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3Tv;<hF
{ aV`4M VWOz
nStartPos += fileAccessI.write(b,0,nRead); A|p O
//if(nThreadID == 1) DP`$gd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X&EcQ
} KrN#>do&<
l(|@ dp
[H$37Hx!
Utility.log("Thread " + nThreadID + " is over!"); OpeK-K
bDownOver = true; _ Js& _d
//nPos = fileAccessI.write (b,0,nRead); FaO=<jYi
} HVG9 C$
catch(Exception e){e.printStackTrace ();} 2@WF]*Z
} `h+ia/
} wlr/zquAE9
R:HF~}
sLh9=Kh`
//打印回应的头信息 BhC.#u/
public void logResponseHead(HttpURLConnection con) ++ !BSQ e
{ )HWf`;VQ
for(int i=1;;i++) @mM'V5_#
{ ek6PMZF:'
String header=con.getHeaderFieldKey(i); 8*yhx
if(header!=null) yZFm<_9>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [U[saR\
Utility.log(header+" : "+con.getHeaderField(header)); #xZ7%
else 'ms&ty*T
break; Dlhb'*@
} f%ude@E3
} 2VaQxctk
=y.!Ny5A
y)N57#e
public void splitterStop() o#Q0J17i?
{ >]uV
bStop = true; |~vo
} 1?s]nU
6FuZMasr*
N3 qtq9{
} ;A)w:"m
3x2*K_A5:Q
7,U^v}$
/* ?:F#WDD
**FileAccess.java Iqe=)
*//文件访问(定位，写) Q$Y ]KV
package NetFox; 9A0wiKp
import java.io.*; I_66q7U"0
?u`+?"'H
./nq*4=
public class FileAccessI implements Serializable{ lJHV c"*/
j?sq i9#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '?Fw]z1$
RandomAccessFile oSavedFile; K4938 v
long nPos; -Bymt[
2uw1R;zw
9&e=s<6dO
public FileAccessI() throws IOException 2t'^
{ &wc%mQV
this("",0); 8z\v|-%Z
} \d~sU,L;]
Hbz>D5$
^gx`@^su
public FileAccessI(String sName,long nPos) throws IOException -7^?40A
{ KICy! "af
oSavedFile = new RandomAccessFile(sName,"rw"); !.>TF+]
this.nPos = nPos; Q _Yl:c
oSavedFile.seek(nPos); LPr34BK
} R$qp3I
D90m..\w
[_W#8{
public synchronized int write(byte[] b,int nStart,int nLen) p^1s9CM%
{ (3kz(6S
int n = -1; 3(D!]ku~m
try{ KG:CVIW Y
oSavedFile.write(b,nStart,nLen); ~"-+BG(5
n = nLen; > cFH=um
} os/_ObPiX
catch(IOException e) O3,IR1
{ := OdjfhY
e.printStackTrace (); &~`Ay4hq
} [|{2&830
nlv8HC
Ubtu?wRBW
return n; n^Co
} uA#uq^3
:ryyo$
3q7Z?1'o
} CjW`cHd
bF'Y.+"dr
pU4k/v555;
/* VKUoVOFvPR
**SiteInfoBean.java &3a1(>(7F
*/ ico%_fp
package NetFox; xb`,9.a7
ktQMkEj#
YK(I'
public class SiteInfoBean { 9C;Hm>WEpP
'n1-?T)
QkMK\Up
private String sSiteURL; //Site's URL c@p4,G
private String sFilePath; //Saved File's Path ,l}mCY
private String sFileName; //Saved File's Name !brXQj8D7
private int nSplitter; //Count of Splited Downloading File H(}Jt!/:
QoagyL
92y<E<n
public SiteInfoBean() $$my,:nH
{//nSplitter的缺省值为5 <_X`D4g]XO
//default value of nSplitter is 5 !V|%n(O"
this("","","",5); 5\hJ&
} JIeKp7;^
>,JLYz|</
xqV>m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .9r+LA{
{ n/ ]<Bc?
sSiteURL= sURL; pv/LTv
sFilePath = sPath; @KtQ~D
sFileName = sName; #Av6BGM|,
this.nSplitter = nSpiltter; f+*wDH
[]opPQ 1
Vaj4p""\F
} a~#MMl
ci]IH]x
'rWu}#Nb
public String getSSiteURL() Mlr]-Gu5Z
{ >cVEr+r9t
return sSiteURL; |g o jb
} g.3 . C?
xc|pl!ns
\_H-TbU8
public void setSSiteURL(String value) ,:RHhg
{ oSGx7dj+
sSiteURL = value; cT8b$P5w
} R4xoc;b
rLt`=bl&&U
ED9uKp<Wbv
public String getSFilePath() ?|Q[QP
{ _oOEMQb
return sFilePath; 9wR-0E )
} vkFfHzR$
Ww(($e!
@|yRo8|
public void setSFilePath(String value) v4X\LsOP
{ ZHA6BVVT
sFilePath = value; .QwwGm
} g~zz[F 8U
z&a%_ ]Q*
!rmXeN]-r
public String getSFileName() Q@M>DA!d^V
{ N#C"@,}Y
return sFileName; eVRFb#EU0e
} -K+" :kiS
eh`sfH
@y)'h]d
public void setSFileName(String value) r3OTU$t?
{ #X~{p4Lr
sFileName = value; Kk?]z7s-4
} l)JNNcej
K|Q|v39{b
=\jp%A1$
public int getNSplitter() ql Z()
{ '%JIc~LJ
return nSplitter; 8H0d4~Wg
} e|ChCvk
cP >MsUZWl
kpxWi=y
public void setNSplitter(int nCount) *k&yD3br-V
{ {Q/XV=
nSplitter = nCount; H.sYy-_]F
} :o!bz>T
} ~ NO9s
YA7h! %52)
([Gb]0
/* j%|#8oV
**Utility.java A6?+$ Hr
*/ a}oFL%=?
package NetFox; /FzO9'kj
*rs@6BSj
y.KFz9Qv
public class Utility { _RzwE$+9
H;#3S<
=(!&8U9
public Utility() XYBvM]
{ jzRfD3_s
fgmu*\x<
Fpz)@0K;
} +`;YK7o
bnso+cA
//线程睡眠 W(5et5DN,
public static void sleep(int nSecond) `# N j8
{ Z/y&;N4
try{ jacp':T
Thread.sleep(nSecond); $d<vPpJ3
} Ek0zFnb[Gx
catch(Exception e) QKj8~l(
{ dNQR<v\IL
e.printStackTrace (); v'x)AbbC
} ^lF'KW$
} s7x&x;-
'X()|{
//日志 f-w-K)y$ht
public static void log(String sMsg) XkG:1H;Q%
{ =qQH,{]c6
System.err.println(sMsg); i_ha^mq3
} p};B*[ki
[| \Z"
-k$*@Hq
public static void log(int sMsg) 5>E]C=maD
{ B%~hVpm,eM
System.err.println(sMsg); 5xHP5+&
} WtT* 1Z
} z>\vYR$
+<\)b(
3LxhQVx2
/* JG]67v{F
**TestMethod.java 9VEx0mkdd
*/ 'p%\fb6`
package NetFox; 7Wd}H Z
k0%*{IVPN
*]L(,_:"
public class TestMethod { 73:y&U
.7h:/d Y:
In[!g
public TestMethod() S;!l"1[;
{ ///xx/weblogic60b2_win.exe -tQi~Y[]
try{ 0QWc1L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9n(.v}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t`b!3U>I
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;y"=3-=vM"
fileFetch.start(); q_5hKipd\b
} hKG)* Q
catch(Exception e){e.printStackTrace ();} 7P&O{tl(
X?2ub/Nr#Y
gpIq4Q<
} .u+ZrA#
:A~6Gk92A
,'7 X|z/_>
public static void main(String[] args) -y@# ^SrJ
{ 4pYscB
new TestMethod(); %K9 9_Cl3
} ;9WS#>o
} Yqpe2II7
点击下载更多相关资料